# Pencils, charcoal, pastels and crayons: research notes

Date: 2026-10-25. Scope: hand-held dry and wax drawing media sold as pencils, sticks, blocks or pans: wood-cased graphite pencils (writing and drawing), mechanical and clutch pencils, woodless graphite, coloured pencils (wax, oil and water-soluble), charcoal (vine, willow, compressed, charcoal pencils), dry pastels (hard, soft, pastel pencils, pan pastels), oil pastels and wax crayons. One register; the `medium` split does the dividing. Not refill leads (sibling `ink-cartridges`, "Refills, Leads & Ink Cartridges"), not markers or highlighters (sibling `pens`), not sharpeners (sibling `desk-paper-tools`, presumed), not erasers (sibling `correction-products`, whose register has a pencil-erasers family; checked 2026-10-25), not chalkboard or sidewalk chalk (left to `stationery-boards` and the play leaves), not paint sticks or watercolour blocks (sibling `paint`). Overlaps to watch: `play-dough` ("Play Dough, Putty & Drawing") may hold kids' drawing toys that bundle crayons; Blick files water-soluble wax pastels (Neocolor II) and oil pastels under "crayons", so the crayon/oil-pastel line is blurry at retail. The register keeps both here and leaves bundled toy kits to the play leaf. Edge products (our calls, 2026-10-25, unsourced): Conté sticks file under `dry pastel`; mixed-media sketch kits take the medium most of their pieces use; grease pencils and china markers are wax marking tools for non-paper surfaces and stay out of this leaf (closest sibling `pens`). The register covers US rules only; EN 71-3 and other non-US rules are not in it.

Vertical: the brief says `supplies`; the skill's schema.json enum is `formulations, machines, fashion, furnishing, other`, and the validator rejects `supplies` (tested: "schema vertical: 'supplies' is not one of [...]"). The JSON carries `other` so validate, render and viewer run clean; the catalog entry still says `supplies`. Flagged in the report.

Quote labels: **verbatim** = the sentence in quotation marks was in text I read myself (curl plus HTML stripping, or pdftotext on a downloaded PDF; raw text in the scratchpad `pencils/` folder); **fetched excerpt** = the WebFetch tool summarised or quoted it and I did not see the raw text; **search excerpt** = from a search-engine summary. This run had no web search available (the session's search budget was spent before it started), so every source below was reached by a known or linked URL; there are no search excerpts.

## Seed

Seed output (verbatim):

- Example: car-tyres `treadwear_grade`: "a number that is on every listing and still needs a judgement attached, because experts know it only compares within one manufacturer's range."
- Persona: "An industrial designer, who thinks in materials, joins and what the manufacturer saved money on"

1. **What is the pencils equivalent of treadwear?** The graphite grade (HB, 2B, #2). It is on every pencil, it is the number people compare on, and it compares only within one brand: Wikipedia says "Manufacturers distinguish their pencils by grading them, but there is no common standard" (verbatim) and Pencils.com says "a #2 or HB pencil from one brand will not necessarily leave the same mark as a #2 or HB pencil from another brand" (verbatim). Faber-Castell's Grip 2001 numbering even maps "2½ = HB", not 2 = HB (Wikipedia, verbatim). **Kept** as `graphite_grade` with judgement 1. A second treadwear turned up in colour media: lightfastness has a real standard (ASTM D6901, I to V) but most brands rate by their own stars per colour, and student lines rate nothing. **Kept** as `lightfastness` with judgements 2 and 3.
2. **What would the industrial designer notice first?** The binder, which is the material decision behind every medium in the leaf (clay, wax, oil, gum, none), and the joint between core and case. The binder became the mechanism and the `binder` facet. The joint: Faber-Castell glues "over the entire lead in the wooden shaft (not just point-gluing)" (verbatim) and Wikipedia notes wooden pencil lead "is bonded to the outer wooden case, therefore providing more lead protection and strength" (verbatim), which is also why mechanical leads break. **Kept** inside `format` and `lead_mechanism`. **Dropped**: casing wood as a facet (incense cedar versus basswood or alder). Wikipedia says most pencils are incense cedar and alternatives are basswood and alder, and Prismacolor's cedar barrels "sharpen cleanly" (Blick, verbatim), but no second source says how much the wood changes sharpening. **Dropped**: core diameter as a quality signal. Polychromos, Luminance, Prismacolor Premier and Holbein all list 3.8 mm cores (Blick, verbatim) across oil and wax lines, so 3.8 mm splits nothing.

## Sources and what each supports

### Regulators and standards bodies

**16 CFR 1500.14(b)(8), via Cornell LII** https://www.law.cornell.edu/cfr/text/16/1500.14
- verbatim: LHAMA "provides that, as of November 18, 1990, 'the requirements for the labeling of art materials set forth in the version of the standard of the American Society for Testing and Materials ["ASTM"] designated D-4236 ... shall be deemed to be a regulation issued by the Commission'".
- verbatim: "The producer or repackager shall have a toxicologist review as necessary, but at least every 5 years, art material product formulation(s) and associated label(s)".
- verbatim: "Statement of Conformance—'Conforms to ASTM Practice D-4236,' or 'Conforms to ASTM D-4236,' or 'Conforms to the health requirements of ASTM D-4236.'"
- verbatim: "All art materials that require chronic hazard labeling pursuant to this section must include on the label ... a statement that such art materials are inappropriate for use by children."
- Supports: `safety_seal` (the legal floor is the D-4236 line). Confidence high.

**15 U.S.C. 1277 (LHAMA), via Cornell LII** https://www.law.cornell.edu/uscode/text/15/1277
- verbatim: "The Commission may bring an action under section 1267 of this title to enjoin the purchase of any art material required to be labeled under this chapter which is for use by children in pre-kindergarten, kindergarten, or grades 1 through 6."
- Supports: the grade 6 line. Confidence high.

**15 U.S.C. 1278a, via Cornell LII** https://www.law.cornell.edu/uscode/text/15/1278a
- verbatim: "beginning on the date that is 3 years after August 14, 2008, subparagraph (B) shall be applied by substituting '100 parts per million' for '300 parts per million'".
- verbatim (re-read 2026-10-25), (f) More stringent lead paint ban: "the Commission shall modify section 1303.1 of its regulations ... by substituting “0.009 percent” for “0.06 percent” in subsection (a) of that section."
**16 CFR 1303.1, via Cornell LII** https://www.law.cornell.edu/cfr/text/16/1303.1 (curl 2026-10-25)
- verbatim: "Toys and other articles intended for use by children that bear “lead-containing paint”"; "0.06 percent is reduced to 0.009 percent effective August 14, 2009".
- Supports: 90 ppm (0.009 percent) lead limit on paint on children's articles, two sources with 1278a(f). Applying it to a children's pencil's lacquered casing is our reading, following the blind check.
**CPSC, Total Lead Content** https://www.cpsc.gov/Business--Manufacturing/Business-Education/Lead/Total-Lead-Content (curl returned Akamai "Access Denied"; WebFetch worked)
- fetched excerpt: "children's products that contain more than 100 ppm lead in an accessible component to be a banned hazardous substance".
- Supports: the 100 ppm figure (two sources). Confidence high.

**15 U.S.C. 2052, via Cornell LII** https://www.law.cornell.edu/uscode/text/15/2052
- verbatim: "The term 'children's product' means a consumer product designed or intended primarily for children 12 years of age or younger."
**CPSC, Art and Craft Safety Guide, Pub. 5015 (PDF, pdftotext)** https://www.cpsc.gov/s3fs-public/5015.pdf
- verbatim: "Up to 12 years of age (Pre-kindergarten through Grade 6):" (section heading).
- verbatim: "Children's products that meet this definition include, but are not limited to, crayons, chalk, paint sets, colored pencils, and modeling clay. It is recommended that parents/guardians purchase only those products labeled with the statement 'Conforms to ASTM D-4236' ... and that do not have any cautionary warnings on the label."
- verbatim (Pastels): "Some pigments such as chrome yellow (lead chromate) may be toxic (e.g., chronic inhalation may cause lung cancer and skin contact may cause irritation). Avoid pigments with lead chromate." "Dust may be irritating if inhaled, particularly to asthmatics. Use less dusty supplies. Do not blow excess dust, tap the drawing instead." "Oil pastels are a safe alternative because they create less dust."
- verbatim (Charcoal): "Dust may be irritating if inhaled." "Remove excess dust by tapping, not blowing."
- verbatim (Pencils): "Potentially hazardous components include graphite and some pigments in colored pencils."
- Supports: 12 years and grade 6 band (with 2052), dust as the main hazard, oil pastels as the low-dust alternative. Confidence high.
- **CPSC Art Materials business guidance** https://www.cpsc.gov/Business--Manufacturing/Business-Education/Business-Guidance/Art-Materials (WebFetch only). fetched excerpt: "Art materials must undergo a toxicological assessment at least every 5 years"; "The requirements under LHAMA are not considered a safety rule that requires certification under section 14(a)(1) of the Consumer Product Safety Act." Second source for the 5-year review; not cited in the JSON.

**ACMI, Art Materials Safety** https://acmiart.org/materials-safety (and https://acmiart.org/classroom-art-materials-safety, same text)
- verbatim: "The AP Seal identifies art materials that are certified in a toxicological evaluation by a board certified toxicologist (medical expert) to contain no materials in sufficient quantities to be toxic or injurious to humans, including children".
- verbatim: "Check for the CL Seal on creative products for kids in seventh grade or older. Never give children in sixth grade or younger a product with the CL Seal."
- verbatim: CL "Appears on only a small percentage of adult art materials, and on no children's materials".
- Supports: `safety_seal` values and the grade 6 rule. Confidence high.

**ASTM D6901 and D4236 product pages** (astm.org) returned 404 shells, and the page text says AI use of ASTM standards is prohibited, so the standards themselves were not read. D6901 is described from CPSA below.

### Enthusiast community

**Colored Pencil Society of America, ASTM Standard** https://cpsa.org/about/astm-standard/
- verbatim: CPSA "worked diligently in conjunction with ASTM International ... to create D6901, the Standard Specification for Artists' Colored Pencils, which was published in 2003."
- verbatim: "Lightfastness categories are I, II, III, IV, and V with I being the best (very lightfast) and V being the worst (fugitive/not lightfast). Only pencils with lightfastness ratings of either I or II can be labeled as complying with the standard. For an entire line of colored pencils to be labeled as D6901 compliant, every pencil must have a lightfast rating of either I or II."
- verbatim: "Unfortunately, complying with the standard is not mandatory."
**CPSA, Lightfastness** https://www.cpsa.org/lightfastness (redirects to https://cpsa.org/about/lightfastness/; re-read by curl 2026-10-25, sentence confirmed; now reference `cpsa_lightfastness`)
- verbatim: "The least stable colors are hot pinks, purples, blues, reds, and oranges, while browns, grays, and other neutrals generally remain unchanged."
**CPSA, Colored Pencil Defined** https://cpsa.org/about/colored-pencil-defined/
- verbatim: "colored pencil cores contain both waxes and oils and varying proportions of pigments, fillers, and binders."
- verbatim: "BUYER BEWARE: Advertising and packaging may claim a product is 'professional' grade and lightfast, but sadly, that is not necessarily true."
- verbatim: "Inexpensive brands are of poor quality for lightfastness and pigmentation."
- Supports: `lightfastness` values, judgement 2. Confidence high.

### Primers

**Wikipedia, Pencil** https://en.wikipedia.org/wiki/Pencil
- verbatim: "The amount of clay content added to the graphite depends on the intended pencil hardness (lower proportions of clay makes the core softer)"; strings are "tempered in a kiln" then "dipped in oil or molten wax".
- verbatim: "Manufacturers distinguish their pencils by grading them, but there is no common standard. Two pencils of the same grade, but different manufacturers, will not necessarily make a mark of identical tone nor have the same hardness."
- verbatim: "The standard writing pencil is graded HB." Table row: "HB #2". "Faber-Castell uses a different equivalence table in its Grip 2001 pencils: 1 = 2B, 2 = B, 2½ = HB, 3 = H, 4 = 2H."
- verbatim: graphite marks are "resistant to moisture, most solvents, ultraviolet radiation and natural aging".
- verbatim: woodless pencils "provide greater economy, as the entire pencil is used."
- verbatim: "Most pencils today are made from this timber [incense cedar] ... Less popular alternatives to cedar include basswood and alder."
- verbatim footnote (Petroski 1990): "graphitic carbon content, for example, varies from about 30 to about 65 in a variety of different pencils bearing the same designation." Single source; kept here only.
- verbatim: Koh-i-Noor 10H to 8B (20 grades), Mitsubishi Hi-uni 10H to 10B (22), Derwent 9H to 9B (20), Staedtler Mars Lumograph 10H to 12B (24). Single source; the values list collapses grades into bands instead.

**Pencils.com, The HB graphite grading scale** https://pencils.com/pages/hb-graphite-grading-scale
- verbatim: "In reality however, there is no specific industry standard for the darkness of the mark to be left within the HB or any other hardness grade scale. Thus, a #2 or HB pencil from one brand will not necessarily leave the same mark as a #2 or HB pencil from another brand."
- verbatim: "In Japan, consumers tend to prefer softer darker leads; so an HB lead produced in Japan is generally softer and darker than an HB from European producers." Single source; attributed in the JSON.
- verbatim: "Softer pencils will dull faster than harder leads and require more frequ[ent sharpening]" (line truncated in the strip at "frequ").
- verbatim: "Generally, an HB grade about the middle of the scale is considered to be equivalent to a #2 pencil".

**Wikipedia, Colored pencil** https://en.wikipedia.org/wiki/Colored_pencil
- verbatim: "Artist and professional-grade pencils are made with higher concentrations of high-quality pigments than student-grade colored pencils. Their lightfastness ... is also measured and documented." "They are also typically available as individual pencils."
- verbatim: student lines "do not usually include a lightfastness rating, and core composition and pigment-binder ratio vary, even between products manufactured by the same company." "their color range is smaller, often limited to 24 or 36 colors." (single source; not in JSON)
- verbatim: oil binder gives "the ability to create fine details with less wax bloom".
- verbatim: watercolour pencils "can be used dry like traditional colored pencils, or applied wet to create watercolor effects."

**The Virtual Instructor, Oil-based vs wax-based colored pencils** https://thevirtualinstructor.com/blog/oil-based-vs-wax-based-colored-pencils
- verbatim: "Wax-based pencils are generally easier to erase than oil-based pencils and are usually softer." "wax-based pencils are prone to wax bloom ... Wax bloom that develops on a drawing can be easily wiped away with a damp cloth". "Since wax-based pencils are softer than oil-based pencils, the cores tend to break easily."
- verbatim: oil pencils "are generally only produced as a premium line of pencil"; "the pencil keeps a sharper point for a longer period of time"; "oil-based pencils do not produce wax-bloom".
- verbatim: "the only way to know for sure which you prefer is to experiment."

**Wikipedia, Lightfastness** https://en.wikipedia.org/wiki/Lightfastness
- verbatim: "On the Blue Wool Scale the lightfastness is rated between 1–8. 1 being very poor and 8 being excellent lightfastness." "On ASTM scale the lightfastness is rated between I-V. I is excellent lightfastness and it corresponds to ratings 7–8 on Blue Wool Scale. V is very poor lightfastness and it corresponds to Blue Wool scale rating 1."
- Table (verbatim cells): Blue Wool 4 = ASTM III, "15–50 years" normal display; 6 = II, "50–100 years"; 7 = I, "over 100 years".

**Wikipedia, Pastel** https://en.wikipedia.org/wiki/Pastel
- verbatim: "Soft pastels: ... The sticks have a higher portion of pigment and less binder. The drawing can be readily smudged and blended, but it results in a higher proportion of dust. Finished drawings made with soft pastels require protecting, either framing under glass or spraying with a fixative".
- verbatim: "Hard pastels: These have a higher portion of binder and less pigment, producing a sharp drawing material that is useful for fine details. ... the colors are less brilliant".
- verbatim: "Oil pastels: ... do not require a fixative."
- verbatim: "Only pastels with lightfast pigments are used. As it is not protected by a binder the pigment in pastels is especially vulnerable to light."
- verbatim: "Pastels are a dry medium and produce a great deal of dust, which can cause respiratory irritation. More seriously, pastels might use the same pigments as artists' paints, many of which are toxic. For example, exposure to cadmium pigments ... can lead to cadmium poisoning." "All brands that have the AP Label ... are not considered toxic, and they might use extremely insoluble varieties of cadmium or cobalt pigments".

**Wikipedia, Oil pastel** https://en.wikipedia.org/wiki/Oil_pastel
- verbatim: "uses mixture of non-drying oil and wax as binder".
- verbatim: "Because oil pastels never dry out completely, works are often protected by applying a special fixative to the painting or by placing the painting in a sleeve before framing." (disagrees with the Pastel article; judgement 8)

**Wikipedia, Crayon** https://en.wikipedia.org/wiki/Crayon
- verbatim: crayons are "made mostly of paraffin wax"; they are "particularly good instruments for teaching small children to draw".
- verbatim: "Colin Snedeker ... developed the first washable crayons in response to consumer complaints regarding stained fabrics and walls."
- verbatim: in 2000 the CPSC "found traces of asbestos fibers in three crayons ... CPSC declared the risk to be low". History only; not in JSON.

**Wikipedia, Charcoal (art)** https://en.wikipedia.org/wiki/Charcoal_(art)
- verbatim: "Both compressed charcoal (held together by a gum or wax binder) and charcoal sticks (wooden sticks burned in a kiln without air) are used." "The removable properties of willow and vine charcoal, through dusting and erasing, are favored by artists for making preliminary sketches ... This also makes such charcoal less suitable for creating detailed images." "Charcoal pencils consist of compressed charcoal enclosed in a jacket of wood."

**Wikipedia, Mechanical pencil** https://en.wikipedia.org/wiki/Mechanical_pencil
- verbatim: "Mechanical pencil mechanisms use only a single lead diameter." "The most common lead sizes are 0.5 mm and 0.7 mm, whose line widths provide a favourable balance between precision and strength."
- verbatim: "The Japanese JIS standard for mechanical pencil leads, states that the actual diameter for '0.5 mm' lead (for example), should range from 0.55 mm to 0.58 mm." Single source; trimmed from the JSON.
- verbatim: an auto-rotation mechanism "rotates the pencil lead 9 degrees counter-clockwise every time the lead is pressed on to the paper". Single source; the 9 degrees stays here.
- verbatim: DelGuard "causes the lead sleeve to extend outward when excessive pressure is applied at an angle."
- verbatim: "Wooden pencil lead is bonded to the outer wooden case, therefore providing more lead protection and strength."

### Brand spec sheets

**Faber-Castell UK, Polychromos tin of 60** https://www.faber-castell.co.uk/products/110060
- verbatim bullets, in this order: "High-quality acid-free pigments in bright colours, unsurpassed lightfastness"; "Soft, vibrant colour laydown"; "Water-resistant and smudge-proof"; "Thick 3.8 mm lead"; "High break resistance due to secural bonding process (SV)"; "Available in individual colours and various assorted sets".
- Faber-Castell global Polychromos page https://www.faber-castell.com/products/polychromos, verbatim: "The lead is protected against breakages with a special glue over the entire lead in the wooden shaft (not just point-gluing)."
- The field order is the tell: lightfastness, water resistance, core size, break resistance, open stock. No binder named on the brand page; Blick names it.

**Faber-Castell colour table (PDF, pdftotext -layout)** https://www.faber-castell.co.uk/-/media/Faber-Castell-new/PDF/en/Farbtabelle-AG-ENG-0214.ashx?sc_lang=en-GB
- Column header "Lightfastness"; ratings shown as `*`, `**`, `***` per colour per product. Row read on page 1 where alignment is clean: "119 light magenta  *  ...  *" (Polychromos pencils column: one star). Dated 2014 (file name 0214). I tried to count the star distribution for the whole Polychromos column, but pdftotext shifts columns on later pages and the count (32/16/23) is not trustworthy, so no share is given.

**Pentel (original)** https://www.pentel.com/products/orenz-mechanical-pencil. The blind check found it redirects to the homepage; reference removed 2026-10-25.
**Pentel, lead refills collection** https://www.pentel.com/collections/lead-refills (curl 2026-10-25, titles from the page's product JSON; reference `pentel_leads`)
- verbatim titles: "Pentel Super Hi-Polymer Lead Refill (0.2mm) Super Fine, HB, 12 pcs/Tube 2-Pk"; "Pentel Super Hi-Polymer Lead Refill (0.3mm) Extra Fine, HB, 12 pcs/Tube 2-Pk"; "Pentel Super Hi-Polymer Lead Refill (0.5mm) Fine, 12 pcs/Tube, Assorted Packs - 2B / 3-Pk"; "Pentel Super Hi-Polymer Lead Refill (0.9mm) Medium, HB, 30 pcs/Tube"; "Pentel Super Hi-Polymer Lead Refill (1.3mm) HB, 8pcs/Tube". Supports: refills in 0.2 to 1.3 mm, titled by diameter and grade.
- earlier (from the dead URL, kept for the record) listing titles: "Super Hi-Polymer® Lead, 0.7mm, HB, 30 Pieces per Tube"; "Pentel GraphGear 1000 ... Drafting Mechanical Pencil (0.5mm)"; "Pentel Orenz Nero Mechanical Drafting Pencil, Automatic Lead Advance". Supports: diameter and grade sit in brand-store titles.

**uni-ball UK, Kuru Toga** https://www.uniball.co.uk/products/kuru-toga
- verbatim: "Its unique gear mechanism rotates the lead each time it comes into contact with the paper, so your tip remains cone-shaped and is far more resistant to breaking."

**Zebra Pen, DelGuard** https://www.zebrapen.com/products/delguard-mechanical-pencil
- verbatim: "DelGuard's double spring, patent-pending mechanism ensures lead is secure adding protection from breakage with all writing styles, vertically or on an angle."

### Retail listings (Blick; raw HTML, descriptions pulled from embedded JSON, punctuation partly stripped by the page's own data)

**Blick category pages** https://www.dickblick.com/categories/coloredpencils/ , /categories/oilpastels/ , /categories/mechanicalpencils/ , /categories/charcoal/ , /categories/crayons/ , /categories/pastels/
- verbatim filter lists: coloured pencils "Professional Grade Colored Pencils (41) Professional Grade Watercolor Pencils and Sets (34) Kids' Colored Pencils (30) Open Stock Colored Pencils (26) Student Grade Colored Pencils (19) Colored Pencil Blenders (9) Oil Based Colored Pencils (8)"; oil pastels "Professional Grade Oil Pastels (13) Kids' Oil Pastels (10) Student Grade Oil Pastels (9)"; mechanical pencils "Mechanical Pencils (39) Lead Refills and Accessories (27) Lead Holders and Clutch Pencils (18) Lead Pointers (8)".
- The crayon category lists Neocolor II "water-soluble wax pastels", Sennelier oil pastels and Cray-Pas oil pastels alongside Crayola Crayons.
- Supports: `user_grade` (three tiers are how a specialist retailer shelves the category), `open_stock`, `binder`, `water_soluble`, and the crayon/oil-pastel overlap.

**Blick product pages** (each https://www.dickblick.com/products/<slug>/)
- `faber-castell-polychromos-pencils`: "Pigmentrich oilbased cores Thick 38 mm leads California incense cedar casings"; "rated from good to maximum for lightfastness". Icons: AP Non-Toxic, CL Cautionary Label.
- `derwent-lightfast-colored-pencils`: "thick oilbased cores that are rich in pigment and 100% lightfast meaning their color will remain vibrant for up to 100 years under museum conditions"; "every Derwent Lightfast Colored Pencil complies with the ASTM D6901 international lightfast testing standard as well as Blue Wool Scale ISO 105". Icon: AP.
- `caran-dache-luminance-colored-pencils`: "Thick 38 mm cores packed with lightfast pigments Premium California incense cedar casings"; "meeting the rigorous requirements of ASTM D6901". Icon: AP.
- `prismacolor-premier-colored-pencils`: "thick soft 38 mm core"; "Housed in round cedar barrels ... they sharpen cleanly and evenly"; "To view the Prismacolor Colored Pencils Lightfast Color Chart, please click here."
- `rembrandt-soft-pastels`: "minimal amounts of kaolin clay as a binder"; "just firm enough to give you control ... without the crumbling that sometimes happens with extrasoft pastels"; "Completely free of heavy metals like cadmium cobalt and lead"; "Full sticks are wrapped and sold individually or in sets". Icons include CL Cautionary Label and Prop 65 for some items.
- `sennelier-soft-pastels`: "minimal amounts of natural binders"; "No fillers or clays are used"; "so soft that a gentle stroke will deliver a solid powerful line". Icons: AP, CL, Prop 65.
- `sennelier-oil-pastels`: "oil pastels never dry out"; "a high degree of lightfastness (with the exception of metallic and fluorescent colors)".
- `caran-dache-neocolor-ii-artists-crayons`: "Professional watersoluble wax pastels"; "Add water and they instantly dissolve into vibrant brushlike washes".
- `generals-compressed-charcoal`: "Available in 2B 4B and 6B hardness levels"; "stronger than vine charcoal".
- `winsor-newton-vine-charcoal-packs`: title "Winsor & Newton Vine Charcoal Packs".
- `crayola-crayons`: "For ages 3+"; icon AP.
- `dixon-ticonderoga-pencils`: "This set of 10 No 2 pencils".
- `pentel-sharp-mechanical-pencil`: "Preloaded with Pentel HiPolymer HB lead ... features a fixed sleeve that protects the lead when used with templates or rulers".
- `staedtler-mars-technico-780-lead-holder`: "holds 2 mm leads and features an integrated pushbutton sharpener".
- `learning-resources/product-info/health-safety/`: "we label products with the following ACMI symbols when applicable"; "In cases where a product may be used in pre-school or primary school classes (K-6) ... we strongly suggest purchasing materials that are AP certified non-toxic products."

What this tells the scraper: on a specialist retailer, medium, format, water-solubility and charcoal type are in the product name; grade (HB, 2B, No 2) and lead diameter are in the name for graphite and mechanical pencils; binder, lightfastness claims and core size are in the description; per-colour lightfastness is only in brand colour charts; AP or CL seals are icons on Blick and on the package. Amazon, Walmart and Target were not attempted (earlier runs record that they block fetches), so every facet not confirmed on Blick names is marked `researched`.

### Could not reach

astm.org (404 shells), Derwent's own lightfast page (404), Caran d'Ache US Luminance page (navigation only), Prismacolor.com (empty), Staedtler Mars Lumograph page (404), JetPens guides (403, Wayback empty), Jackson's Art blog (empty), CPSC pages via curl (Akamai block; WebFetch worked for two), Crayola safety pages (navigation shell only), Princeton EHS art safety (empty). No enthusiast forum or Reddit was reached; CPSA stands in as the community voice for coloured pencils, and there is no equivalent for pastels or graphite in this run.

## Data points used for derived metrics

- `lightfast_share`: the definition rests on CPSA ("every pencil must have a lightfast rating of either I or II" for a whole-line claim) and on per-colour ratings in Faber-Castell's table. No worked example is given because the table's column alignment broke on later pages. Derwent Lightfast and Luminance score 100 percent by their whole-line D6901 claims (Blick).

## Against the existing add-on schema

The add-on `supplies/stationery/add-ons/pencil.jsonc` is empty (`{}`), and so is `stationery-standard.jsonc`. `supplies-standard.jsonc` carries `high_signal_markdown` and a `sizing` block (`size_stated`, `pack_count`, `pieces_included_text`, `dimensions`, `capacity`, `weight`, `measurements_text`). Proposals only; nothing edited.

| Facet in this register | In schema today | Proposed kind under AGENTS.md | Note |
|---|---|---|---|
| medium | no | vertical anchor for the leaf: enum [graphite, coloured_pencil, charcoal, dry_pastel, oil_pastel, crayon] | Every row has one, text states it, and it gates every other field. |
| user_grade | no | hard filter, enum [kids, student, artist] | Text-derived from line name; augment from a brand-line lookup. |
| format | no | hard filter, enum [wood_cased, mechanical_or_clutch, stick_block_pan] | Borderline photo fact, but a mechanical pencil and a woodless stick are often indistinguishable in a set photo, and the name always says it. Keep. |
| graphite_grade | no | category quality currency (graphite and charcoal rows only): enum of grade bands, plus `graded_set` | The number buyers compare on. Dense on titles; willing to augment (default HB for writing pencils). |
| lead_diameter_mm | no | hard filter, number, inside `sizing` | Brands put the size in brackets in the variant title (Pentel GraphGear "(0.5mm)"), the mark of a field that can differ between variants of one model, so it belongs in `sizing` under rule 2. Whether a given model ships in several sizes was not checked in this run. |
| water_soluble | no | hard filter, boolean | In the name; cheap. |
| lightfastness | no | category quality currency for artist colour rows: enum [whole_range_d6901, rated_per_colour, not_rated] | The canonical comparison for artist colour. Worth augmenting for artist lines only; the per-colour detail goes to markdown. |
| safety_seal | no | hard filter, enum [ap, cl, d4236_only, not_stated] | AGENTS.md cuts certifications on sight, but this is the governing child-safety marking and the legal labelling standard, not a marketing badge; parents filter on it literally. Argue for an exception. |
| binder | no | high_signal_markdown | Matters to artists, lives in description copy; one line of markdown is enough. |
| lead_mechanism | no | high_signal_markdown | Named feature (Kuru Toga, DelGuard) in the title; not a filter for most buyers. |
| pastel_hardness | no | high_signal_markdown | Line-level copy only. |
| charcoal_type | no | hard filter, enum [vine_or_willow, compressed] | In the name; changes erasability. Could fold into the medium enum instead. |
| open_stock | no | high_signal_markdown | A line property, not a row property; markdown states it once. |
| washable | no | hard filter, boolean (crayons) | Parents filter on it. |
| pack_count (colours per set) | yes, `sizing.pack_count` | sizing | Already present; it is the denominator of `lightfast_share`. |

Add-on fields this register considers noise: none exist yet. From the standard, `sizing.capacity` and `sizing.weight` say nothing for this leaf (a set of pencils is bought by count and colour, not grams), and `dimensions` matter only for crayon size for small hands, which the photo shows.

## Branches

Every `when` value is a value of its split facet. Answer-to-value rules: split 1 offers the six values in plain words ("ordinary (graphite) pencil" is `graphite`, "chalk pastel" is `dry pastel`, hard pastels and pastel pencils included; "crayon" is `crayon`); split 2 maps "child 12 or under" to `kids`, "teen or adult" to `student`, "serious art" to `artist`, and a child 12 or under doing serious art still maps to `kids`, because ACMI's rule is "Never give children in sixth grade or younger a product with the CL Seal" whatever the tier (our call, following ACMI); split 3 maps "wooden pencil" to `wood-cased pencil`, "mechanical pencil" to `mechanical or clutch pencil` (lead holders included), "bare stick or pan" to `stick, block or pan`.

**Split 1, medium**
- graphite → ask format, graphite_grade. "Graphite pencils come down to grade" (summary); format: graphite comes wood-cased, mechanical and woodless (Wikipedia Pencil, Mechanical pencil). Irrelevant: lightfastness, because graphite marks are "resistant to ... ultraviolet radiation and natural aging" (Wikipedia Pencil); binder, pastel_hardness, charcoal_type, because each facet's definition restricts it to coloured pencils, dry pastels or charcoal.
- coloured pencil → ask water_soluble, binder, lightfastness. Watercolour pencils are a separate category (Blick filters; Wikipedia); binder is the wax/oil choice (CPSA, Virtual Instructor); lightfastness is "the single most important quality issue to colored pencil artists" (CPSA). Irrelevant: graphite_grade, charcoal_type, pastel_hardness by definition.
- charcoal → ask charcoal_type, format. Vine versus compressed (Wikipedia Charcoal); charcoal comes as sticks and pencils (Wikipedia Charcoal). Irrelevant: binder, pastel_hardness by definition. (2026-10-25: graphite_grade removed from this leg. Only compressed charcoal and charcoal pencils carry B grades (Blick General's "2B 4B and 6B"); vine and willow do not, and a branch cannot condition on charcoal_type. graphite_grade stays a filter for compressed rows. Charcoal does not make lightfastness irrelevant: no source here says charcoal marks resist light.)
- dry pastel → ask pastel_hardness, safety_seal, lightfastness. Hardness is the binder ratio (Wikipedia Pastel); safety: CPSC guide on pastel pigments and dust, and Sennelier soft pastels carry CL icons (Blick); lightfastness: pastel pigment "is especially vulnerable to light" (Wikipedia Pastel). Pastels take the brand-claim or per-colour lightfastness values, since D6901 covers coloured pencils only. Irrelevant: graphite_grade, binder, charcoal_type by definition.
- oil pastel → ask lightfastness. Sennelier: lightfast "with the exception of metallic and fluorescent colors" (Blick), a brand-level claim, which is the value "whole range lightfast, brand claim" with exceptions noted. Irrelevant: graphite_grade, binder, pastel_hardness, charcoal_type by definition (pastel_hardness is defined for dry pastels).
- crayon → ask washable, safety_seal. Chain: crayons are the small-children medium (Wikipedia Crayon) and are named children's art materials (CPSC guide), so the child-safety seal applies; washable crayons exist for stained walls and clothes (Wikipedia Crayon). Irrelevant: graphite_grade, binder, pastel_hardness, charcoal_type by definition.

**Split 2, user_grade**
- kids (12 and under, pre-K to grade 6: 15 USC 2052, 15 USC 1277, CPSC 5015 heading, ACMI) → ask safety_seal. ACMI: never CL for grade 6 or younger; CPSC: buy D-4236 with no cautionary warnings. (2026-10-25: washable removed, since the facet is defined for crayons only and the crayon branch already asks it; "lightfastness irrelevant" removed, since the cited sentence is about student and scholastic lines, not kids' lines, and "usually" is not "never".)
- artist → ask lightfastness, open_stock. Artist lines document lightfastness and are "typically available as individual pencils" (Wikipedia Colored pencil). (2026-10-25: binder removed. The source runs the other way, oil implies premium, and binder is coloured-pencil-only; the coloured pencil branch already asks it.)
- student: no branch; nothing changes downstream.

**Split 3, format**
- mechanical or clutch pencil → ask lead_diameter_mm, lead_mechanism, graphite_grade. "Mechanical pencil mechanisms use only a single lead diameter" (Wikipedia); mechanisms exist to stop breakage (uni, Zebra); leads are sold by grade (Pentel lead-refills collection, "(0.5mm) Fine, HB" and "- 2B").
- wood-cased pencil, stick, block or pan → lead_diameter_mm and lead_mechanism irrelevant, by their definitions (mechanical and clutch pencils only).

Generic test on the splits: split 1 is specific to this leaf. Split 3 names mechanical pencils and pans and would not read unchanged elsewhere. Split 2 now asks around the 12-and-under line that US art-material and children's-product rules draw ("Child 12 or under, teen or adult, or serious art?"); it stays because the three tiers decide which spec matters (safety seal versus lightfastness), which is category knowledge, not a budget proxy.

## Numbers in category.json and how many sources stand behind each

| Number | Sources |
|---|---|
| Grade 6 / pre-K to grade 6 line for hazard-labelled materials | 15 USC 1277, ACMI, Blick health page, CPSC guide heading |
| Children's products: 12 years or younger | 15 USC 2052, CPSC guide heading |
| 90 ppm (0.009 percent) lead in paint on children's articles | 16 CFR 1303.1, 15 USC 1278a(f) |
| 100 ppm total lead in children's products | 15 USC 1278a, CPSC Total Lead Content (fetched excerpt) |
| Toxicologist review at least every 5 years | 16 CFR 1500.14 (verbatim), CPSC Art Materials guidance (fetched excerpt). In references only |
| ASTM D6901 categories I to V; I or II to comply; published 2003 | CPSA (verbatim), Wikipedia Lightfastness for I to V (2003 is CPSA only; references only) |
| Blue Wool 1 to 8; ASTM I = Blue Wool 7 to 8 | Wikipedia Lightfastness only (Derwent naming both scales is not a second source for the numbers). Single source: numbers removed from prose fields 2026-10-25, kept only in the `wp_lightfastness` reference marked single source |
| D6901 whole-line rule (every colour I or II) | CPSA only; ASTM's page could not be read. Marked in the `lightfastness` backfill note |
| Polychromos 119 at one star | Faber-Castell 2014 table only; removed from prose 2026-10-25, kept in the reference marked 2014 |
| 3.8 mm cores | Faber-Castell UK, Blick (Polychromos, Luminance, Prismacolor, Holbein). In references only |
| 0.5 and 0.7 mm usual lead sizes; 2 mm lead holders | Wikipedia; Blick Staedtler 780 and Wikipedia (2 mm). Pentel's collection sells 0.2, 0.3, 0.5, 0.7, 0.9 and 1.3 mm, so it is a source for the range of sizes, not for 0.5 and 0.7 being usual |
| Pentel refill sizes 0.2 to 1.3 mm | Pentel lead-refills collection; Wikipedia "0.2 mm up to 5.6 mm" for the wider range |
| Compressed charcoal 2B, 4B, 6B | Blick General's; the grade scale itself from Wikipedia and Pencils.com |
| Ages 3+ (Crayola) | Blick Crayola only; a product fact, not a category rule |

## Dropped

- Casing wood and core diameter as facets (see Seed).
- Colour count as a facet: student lines "often limited to 24 or 36 colors" is one source (Wikipedia), and `pack_count` already exists in the standard.
- Graphite carbon content of 30 to 65 percent within one grade (Petroski via Wikipedia): single source.
- Kuru Toga's 9 degrees per stroke and JIS 0.55 to 0.58 mm for 0.5 mm lead: single source (Wikipedia).
- Fixative as a facet: it is a separate product (sibling leaf), and whether oil pastels need it is disputed (judgement 8).
- EN 71-3 (EU toy safety, migration of elements) as a `safety_seal` value: only the Wikipedia EN 71 stub was read; no text on whether crayons fall under it. Worth adding for EU catalogues once sourced.
- Asbestos-in-crayons history (CPSC 2000): resolved by reformulation, CPSC called the risk low; history, not a buying signal.
- Price per stick as a derived metric: fails the generic test.

## Trimmed detail

- `graphite_grade`: Koh-i-Noor offers 20 grades from 10H to 8B, Mitsubishi Hi-uni 22 from 10H to 10B, Derwent 20 from 9H to 9B, Staedtler Mars Lumograph 24 from 10H to 12B (Wikipedia, one source). F is "usually taken to mean 'fineness'" but sharpens no finer (Wikipedia).
- `lead_diameter_mm`: JIS sets real "0.5 mm" lead at 0.55 to 0.58 mm (Wikipedia); 0.9 mm is common in the US but "not considered a standard ISO size" (Wikipedia, ISO 9175-1).
- `lead_mechanism`: rotation is 9 degrees per stroke and keeps the lead "50% narrower" than a standard mechanism (Wikipedia, single source); Pentel Orenz Nero sells "Automatic Lead Advance" (Pentel title).
- `safety_seal`: CL "Appears on only a small percentage of adult art materials, and on no children's materials" (ACMI). Hazard-labelled materials must carry a US address and phone number (16 CFR 1500.14).
- `lightfastness`: Wikipedia's table gives Blue Wool 6 / ASTM II as 50 to 100 years and Blue Wool 7 / ASTM I as over 100 years under normal display; Derwent claims "up to 100 years under museum conditions".
- `pastel_hardness`: Rembrandt's colour numbers encode tone (".5 is the full shade and 7 through 12 are tints", Blick).

## Corrections after the blind check (2026-10-25)

Report: `check.md`. Web search was unavailable in this fix session (budget spent); sources were fetched by known URL with curl into the scratchpad `fix-pencils/`.

1. Fix 1, `user_grade` safety gap: `kids` defined as "made for children 12 and under, grade 6 or younger"; question now "Child 12 or under, teen or adult, or serious art?" (split and cold_start); rationale rewritten around the 12-and-under line; answer mapping in "Branches" (a serious young artist still maps to kids).
2. Fix 2, Pentel: deleted "and they are the sizes Pentel's refills come in"; added that Pentel also sells 0.2, 0.3, 0.9 and 1.3 mm refills; replaced reference `pentel_store` (redirects to homepage) with `pentel_leads` (https://www.pentel.com/collections/lead-refills, read 2026-10-25); dropped the unsourced "0.3 mm for fine technical work" from `range.typical`.
3. Fix 3, AP rule: summary now says ACMI advises the AP seal for children 12 and under and that the register covers US rules only; judgement 4 rewritten (ACMI and Blick advise AP; CPSC floor is D-4236 with no cautionary warnings; AP is a voluntary trade-association programme LHAMA never mentions), `sources_disagree` set true, the claim that LHAMA agrees removed; AP vocabulary now says "voluntary".
4. Fix 3, lead paint: added the 90 ppm (0.009 percent) paint limit to `safety_seal`, with new reference `cfr_1303_1` and a second `usc_1278a` supports line for 1278a(f).
5. Fix 3, scope: `safety_seal` and the summary now say US rules only; scope paragraph says so too.
6. Fix 4, `user_grade` source relabelled `derived` → `researched`, backfill `low` → `medium` (it needs the lightfastness-chart check); the backfill note says student versus artist is sourced for colour media only and graphite and charcoal rows get kids or unassigned. The "safety and washability" sentence in its why text now says the safety seal only.
7. Fix 5, kids → washable: removed (washable is crayon-only; the crayon branch asks it).
8. Fix 5, kids → lightfastness irrelevant: removed (no source for kids' lines).
9. Fix 5, artist → binder: removed (binder is coloured-pencil-only; the coloured pencil branch asks it). A conditional leg cannot be written in the schema.
10. Fix 5, charcoal → graphite_grade: removed for the same reason (only compressed charcoal is graded). Not adopted: the checker's ungraded aside that charcoal should make lightfastness irrelevant, since no source here says so.
11. Fix 6: added reference `cpsa_lightfastness` (https://cpsa.org/about/lightfastness/, sentence re-read) and cited it on `lightfastness`; removed the fading-colours line from `cpsa_defined.supports`; the `lightfastness` text now lists all five colours the source names.
12. Fix 7, `lightfast_share`: removed "(or the brand's top tier)" from the formula; the `why` now says high backfill cost, artist lines with published assortments only, top N. The schema has no cost field on metrics, so the cost lives in the prose. The 2014 date of the Faber-Castell table is now stated in `lightfastness`, judgement 3, the colour-chart grammar and the `fc_colour_table` reference.
13. Fix 8: `safety_seal` backfill `low` → `medium`; the note says Polychromos and Sennelier soft pastels mix AP and CL colours, so a set needs its colour list or package photo.
14. Fix 9: added the value "whole range lightfast, brand claim" to `lightfastness` for pastels (Blick Sennelier oil pastels, now in its evidence); the definition, backfill note and D6901 vocabulary say D6901 covers coloured pencils only. No `when` uses `lightfastness`, so no branch changed.
15. Fix 10: no second source could be fetched (no web search; handprint.com, Faber-Castell global and Wikipedia Blue Wool pages gave nothing). Under the two-source rule, the Blue Wool numbers left the prose fields (definition, vocabulary) and stay only in the `wp_lightfastness` reference marked single source; the ladder grammar's origin says to confirm the equivalence before drawing it; the D6901 whole-line rule is marked CPSA-only in the `lightfastness` backfill note; Polychromos 119 left the prose and stays in the reference dated 2014. The per-colour principle still has two sources (Faber-Castell table, Blick "good to maximum").
16. Fix 11: `lead_diameter_mm`, `graphite_grade` and `washable` stay `researched`, and each hint now says why: the value was seen on brand stores and Blick only, and no marketplace was fetched. `charcoal_type` backfill `none` → `low` with a note on generic mixed sets. `format` hint now says wood-cased is assigned by absence (Part D).
17. Fix 12: medium question now "Ordinary (graphite) pencil, coloured pencil, charcoal, chalk pastel, oil pastel or crayon?" (split and cold_start, 12 words); Conté, mixed-media kits, grease pencils and china markers placed in the `medium` hint and the scope paragraph, as unsourced calls of ours; erasers moved from presumed `desk-paper-tools` to `correction-products`, whose register covers pencil erasers.

## Script problems

None in validate.py, render.py or viewer.py. The only friction is the schema's `vertical` enum, which has no `supplies` value (see the scope paragraph).