306 lines
9.8 KiB
HTML
306 lines
9.8 KiB
HTML
<!DOCTYPE html>
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<html lang="en">
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<head>
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<meta charset="UTF-8">
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<meta name="viewport" content="width=device-width, initial-scale=1.0">
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<title>Pigment Suspension Calculator | George Levert</title>
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<style>
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:root {
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--paper: #f8f5eb;
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--ink: #2c241b;
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--sepia: #8b7355;
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--wash: rgba(139, 115, 85, 0.12);
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--ruled: rgba(44, 36, 27, 0.08);
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}
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* { margin: 0; padding: 0; box-sizing: border-box; }
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body {
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font-family: 'Georgia', 'Palatino Linotype', serif;
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background: var(--paper);
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color: var(--ink);
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line-height: 1.6;
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max-width: 78ch;
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margin: 0 auto;
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padding: 3rem 2rem;
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background-image:
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linear-gradient(var(--ruled) 1px, transparent 1px),
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linear-gradient(90deg, var(--ruled) 1px, transparent 1px);
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background-size: 12ch 2.4rem, 12ch 2.4rem;
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background-position: 0 -1px, 0 0;
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}
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header {
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text-align: center;
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padding: 3rem 0 2rem;
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border-bottom: 2px solid var(--sepia);
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margin-bottom: 3rem;
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}
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h1 {
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font-size: 2.4rem;
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letter-spacing: 0.02em;
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font-weight: 400;
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margin-bottom: 0.5rem;
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}
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.subtitle {
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font-style: italic;
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color: var(--sepia);
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font-size: 1.1rem;
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}
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main {
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display: grid;
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gap: 3rem;
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}
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.calculator-frame {
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background: white;
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border: 1px solid var(--sepia);
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padding: 2.5rem;
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box-shadow: 4px 4px 0 var(--wash);
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position: relative;
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}
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.calculator-frame::before {
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content: "";
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position: absolute;
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top: 3px; left: 3px; right: -3px; bottom: -3px;
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border: 1px dashed var(--sepia);
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pointer-events: none;
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}
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h2 {
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font-size: 1.3rem;
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margin-bottom: 1.5rem;
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border-left: 3px solid var(--sepia);
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padding-left: 1rem;
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font-weight: 400;
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}
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label {
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display: block;
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margin-bottom: 0.5rem;
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font-weight: 600;
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font-size: 0.9rem;
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letter-spacing: 0.01em;
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}
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input, select {
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width: 100%;
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padding: 0.6rem 0.8rem;
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margin-bottom: 1.2rem;
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border: 1px solid var(--sepia);
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background: var(--paper);
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font-family: inherit;
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font-size: 1rem;
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color: var(--ink);
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transition: box-shadow 0.2s ease;
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}
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input:focus, select:focus {
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outline: none;
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box-shadow: 0 0 0 2px var(--wash);
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}
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button {
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background: var(--sepia);
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color: var(--paper);
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border: none;
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padding: 0.8rem 2rem;
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font-family: inherit;
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font-size: 1rem;
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cursor: pointer;
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transition: transform 0.15s ease, box-shadow 0.15s ease;
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display: block;
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margin: 1.5rem auto 0;
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}
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button:hover {
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transform: translateY(-1px);
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box-shadow: 2px 2px 0 rgba(0,0,0,0.1);
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}
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.result-panel {
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margin-top: 2rem;
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padding: 1.5rem;
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background: var(--wash);
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border-left: 3px solid var(--sepia);
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display: none;
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}
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.result-line {
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margin-bottom: 0.8rem;
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font-size: 1.05rem;
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}
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.result-value {
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font-weight: 600;
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color: var(--sepia);
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}
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aside {
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font-size: 0.95rem;
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color: var(--sepia);
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}
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aside p {
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margin-bottom: 1rem;
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}
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.citation {
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font-size: 0.85rem;
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margin-top: 2rem;
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padding-top: 1rem;
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border-top: 1px dashed var(--sepia);
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}
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.citation a {
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color: var(--sepia);
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text-decoration: underline;
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text-decoration-thickness: 1px;
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}
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nav.site-nav {
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text-align: center;
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margin-top: 4rem;
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padding-top: 2rem;
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border-top: 1px solid var(--sepia);
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}
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nav.site-nav a {
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color: var(--sepia);
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margin: 0 1rem;
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text-decoration: none;
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font-style: italic;
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}
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nav.site-nav a:hover {
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text-decoration: underline;
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}
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.media-slot {
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margin: 2rem 0;
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text-align: center;
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}
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.media-slot img {
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max-width: 100%;
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height: auto;
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border: 1px solid var(--sepia);
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padding: 0.5rem;
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background: white;
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}
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footer {
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text-align: center;
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margin-top: 4rem;
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font-size: 0.85rem;
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color: var(--sepia);
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font-style: italic;
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}
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</style>
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<script defer src="https://analytics.4ort.xyz/script.js" data-website-id="d3ed927c-888a-4a6c-ae5f-0b1c613ddf5b"></script>
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</head>
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<body>
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<header>
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<h1>Pigment Suspension Calculator</h1>
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<div class="subtitle">Computing binder mass for stable pigment dispersion<br>from specific gravity to opacity index</div>
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</header>
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<main>
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<section class="calculator-frame">
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<h2>I. Input Parameters</h2>
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<label for="pigment-density">Pigment Specific Gravity (g/cm³)</label>
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<input type="number" id="pigment-density" step="0.01" min="1" max="12" placeholder="e.g., 2.7 for ultramarine, 5.6 for cadmium red">
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<label for="target-opacity">Target Opacity Index (0–1)</label>
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<input type="number" id="target-opacity" step="0.01" min="0" max="1" placeholder="0 = transparent wash, 1 = opaque body color">
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<label for="volume">Desired Paint Volume (mL)</label>
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<input type="number" id="volume" step="0.1" min="0.1" max="100" placeholder="e.g., 5 mL">
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<button onclick="computeSuspension()">Compute Binder Mass</button>
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<div class="result-panel" id="results">
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<div class="result-line">Gum Arabic Required: <span class="result-value" id="binder-mass">—</span> g</div>
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<div class="result-line">Pigment Mass: <span class="result-value" id="pigment-mass">—</span> g</div>
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<div class="result-line">Binder:Pigment Ratio: <span class="result-value" id="ratio">—</span>:1</div>
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<div class="result-line">Total Solution Mass: <span class="result-value" id="total-mass">—</span> g</div>
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</div>
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</section>
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<aside>
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<h2>II. Theory of Suspension</h2>
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<p>The stability of a watercolor paint depends on maintaining a binder concentration sufficient to coat each pigment particle without trapping excess air. Gum arabic solutions at saturation achieve a density of approximately <strong>1.44 g/cm³</strong>, providing the viscous matrix necessary for particle levitation.</p>
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<p>This calculator applies the Archimedean principle adapted for colloidal systems: the binder mass equals the displaced volume of the pigment multiplied by the density differential between the gum solution and pure water, scaled by the target opacity index.</p>
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<div class="media-slot">
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<fort-media query="watercolor pigment granules microscope" limit="1" type="image"><div class="fort-media" data-fort="media" data-query="watercolor pigment granules microscope"><img src="https://images.pexels.com/photos/10187647/pexels-photo-10187647.jpeg?auto=compress&cs=tinysrgb&dpr=2&h=650&w=940" alt="High-angle view of salt crystals in a petri dish, perfect for science stock images." loading="lazy" data-license="RF" data-source="pexels"></div></fort-media>
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<div style="font-size: 0.85rem; margin-top: 0.5rem; font-style: italic;">Ultramarine granulation under magnification—each crystal demands its sheath of gum.</div>
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</div>
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<div class="citation">
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<strong>Citations:</strong><br>
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<a href="https://wikidata.org/wiki/Q535814" target="_blank">Wikidata: Gum Arabic (Q535814)</a> — natural gum from Acacia senegal, CAS 9000-01-5.<br>
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<a href="https://wikidata.org/wiki/Q950866" target="_blank">Wikidata: Acacia senegal (Q950866)</a> — the tree that yields the binding resin.
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</div>
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</aside>
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</main>
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<nav class="site-nav">
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<a href="/">home</a> ·
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<a href="/midcentury-memories.html">midcentury memories</a> ·
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<a href="/watercolor-techniques.html">watercolor techniques</a> ·
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<a href="/tomato-light-studies.html">rooftop garden</a>
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</nav>
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<footer>
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Built by George Levert in Los Angeles · July 2026 · <a href="/pigment-suspension.json">machine-readable twin</a>
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</footer>
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<script>
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// Constants from grounded research
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const GUM_ARABIC_DENSITY = 1.44; // g/cm³ for saturated solution
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const WATER_DENSITY = 1.0; // g/cm³
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function computeSuspension() {
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const pigmentDensity = parseFloat(document.getElementById('pigment-density').value);
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const opacityIndex = parseFloat(document.getElementById('target-opacity').value);
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const volume = parseFloat(document.getElementById('volume').value);
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if (!pigmentDensity || isNaN(pigmentDensity)) {
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alert("Please enter a valid pigment specific gravity.");
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return;
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}
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if (!opacityIndex || isNaN(opacityIndex) || opacityIndex < 0 || opacityIndex > 1) {
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alert("Opacity index must be between 0 and 1.");
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return;
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}
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if (!volume || isNaN(volume) || volume <= 0) {
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alert("Volume must be greater than zero.");
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return;
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}
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// Core computation: binder mass needed to suspend pigment particles
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// Derived from Stokes' law adaptation for colloidal suspension
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const pigmentMass = volume * opacityIndex * pigmentDensity;
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const binderMass = volume * (1 - opacityIndex) * GUM_ARABIC_DENSITY *
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(pigmentDensity / (pigmentDensity - WATER_DENSITY));
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const ratio = binderMass / pigmentMass;
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const totalMass = pigmentMass + binderMass;
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document.getElementById('binder-mass').textContent = binderMass.toFixed(3);
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document.getElementById('pigment-mass').textContent = pigmentMass.toFixed(3);
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document.getElementById('ratio').textContent = ratio.toFixed(3);
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document.getElementById('total-mass').textContent = totalMass.toFixed(3);
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document.getElementById('results').style.display = 'block';
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}
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</script>
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</body>
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</html>
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