59 lines
1.6 KiB
JSON
59 lines
1.6 KiB
JSON
{
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"title": "Watercolor Formulation Calculator Constants",
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"author": "George Levert",
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"date": "2026-07-17",
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"version": "1.0.0",
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"schema": {
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"formula": "BinderMass = PigmentMass × (OpacityIndex ÷ SpecificGravity)",
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"variables": {
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"PigmentMass": {
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"unit": "grams",
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"default": 1.0,
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"description": "Reference mass of pigment"
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},
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"OpacityIndex": {
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"unit": "dimensionless",
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"min": 0.1,
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"max": 1.0,
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"description": "Transparency target (0.1=fully transparent, 1.0=fully opaque)"
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},
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"SpecificGravity": {
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"unit": "dimensionless",
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"min": 1.0,
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"max": 15.0,
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"description": "Density of pigment relative to water"
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},
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"BinderMass": {
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"unit": "grams",
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"description": "Calculated mass of gum arabic required"
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}
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},
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"derivedConstants": {
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"filmThicknessFactor": 2.34,
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"mullingTimeCoefficient": 193,
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"gumArabicConcentration": 0.10
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}
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},
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"sources": {
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"pigmentDefinition": {
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"wikidata": "Q161179",
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"slug": "pigment",
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"description": "material that changes the color of reflected or transmitted light"
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},
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"binderMaterial": {
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"wikidata": "Q535814",
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"slug": "gum-arabic",
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"cas": "9000-01-5",
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"description": "natural gum obtained from Acacia sensu lato tree sap"
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}
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},
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"workedExample": {
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"pigment": "Ultramarine Blue",
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"specificGravity": 2.7,
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"opacityIndex": 0.25,
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"expectedBinderMass": 0.0926,
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"mullingTimeMinutes": 18
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},
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"license": "CC0-1.0"
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}
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