<title>Pigment-Binder Ratios — George Levert</title>
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<metaproperty="og:title"content="Pigment-Binder Ratios — George Levert">
<metaproperty="og:description"content="On the relationship between medium and intention — measured, tested, and learned the hard way on a rooftop in July">
<fort-nav><navclass="fort-nav"data-fort="nav"><ahref="/">George Levert</a><ahref="/films/eames-house-breathes/">Index</a><ahref="/curiosity-rover.html">Curiosity Rover: 14 Years on Mars</a><ahref="/curiosity.html">Curiosity: 14 Years on Mars</a><ahref="/binder-ratios.html"class="active"aria-current="page">Pigment-Binder Ratios</a><ahref="/eames-house.html">The Eames House, or How a Building Learns to Breathe</a></nav></fort-nav>
<p>he first time I realized that watercolor was not just about the paint but about the <em>ratio</em> between pigment and binder, I was working on a study of the Walt Disney Concert Hall — those curves of stainless steel against a sky the color of dried lavender. I had laid a thin wash of cobalt, expecting it to settle into the tooth of my Arches 300lb paper. Instead, it pooled, then cracked as it dried, leaving a map of tiny fractures across what should have been a smooth gradient.</p>
<p>The problem was not the paint. It was the binder ratio — the proportion of gum arabic to pigment to water — that determined whether the wash would hold or fall apart. This is the quiet science that separates a watercolorist from a person with wet paper.</p>
</section>
<section>
<h2>The Numbers</h2>
<p>I've compiled the following ratios from my own testing, cross-referenced with historical formulations from the 19th-century manuscript treatises and modern manufacturer specifications. These are not universal truths — they are working notes from a Los Angeles rooftop, where the humidity in July reaches 45% and the afternoon sun dries a wash in under four minutes.</p>
<table>
<thead>
<tr>
<th>Pigment</th>
<th>P:B Ratio</th>
<th>Behavior at 1:8 (P:W)</th>
<th>Failure Mode</th>
</tr>
</thead>
<tbody>
<tr>
<td>Cobalt Blue (PB28)</td>
<td>1 : 4</td>
<td>Transparent, even laydown</td>
<td>Cracking above 1:6</td>
</tr>
<tr>
<td>Burnt Sienna (PR101)</td>
<td>1 : 3.5</td>
<td>Warm, granulates slightly</td>
<td>Muddy when overworked</td>
</tr>
<tr>
<td>Yellow Ochre (PY43)</td>
<td>1 : 3</td>
<td>Earthy, opaque at full strength</td>
<td>Pasty if binder ratio drops</td>
</tr>
<tr>
<td>Raw Umber (PBr7)</td>
<td>1 : 3.2</td>
<td>Granulates beautifully</td>
<td>Streaks on dry paper</td>
</tr>
<tr>
<td>Alizarin Crimson (PR83)</td>
<td>1 : 5</td>
<td>Stained, luminous</td>
<td>Fades in UV over 5+ years</td>
</tr>
<tr>
<td>Phthalo Green (PG7)</td>
<td>1 : 6</td>
<td>Intensely transparent</td>
<td>Hard to lift; stains paper</td>
</tr>
</tbody>
</table>
<p><strong>Key:</strong> P:B = Pigment-to-Binder (gum arabic) ratio by weight. P:W = Pigment-to-Water ratio by volume. These figures are from my own measurements using a digital scale accurate to 0.01g and a 15ml graduated cylinder. Paper: Arches Cold Press 300lb. Ambient: 28°C, 45% RH.</p>
</section>
<section>
<h2>What the Ratios Teach Us</h2>
<figure>
<imgsrc="https://images.pexels.com/photos/8749125/pexels-photo-8749125.jpeg?auto=compress&cs=tinysrgb&dpr=2&h=650&w=940"alt="Dynamic abstract blue watercolor texture">
<figcaption>A blue watercolor wash — the balance between holding and bleeding. Source: <ahref="https://www.pexels.com/photo/blue-and-white-abstract-watercolor-painting-8749125/"target="_blank">Pexels</a></figcaption>
</figure>
<p>Every pigment has a personality — not a poetic metaphor, but a measurable disposition. Cobalt Blue demands more binder than Yellow Ochre because its particles are finer and more prone to separation. Phthalo Green, with its industrial synthetic origin, holds so tightly to the page that it becomes nearly permanent, a quality that is both its strength and its curse.</p>
<p>The failure modes are instructive. When I say a wash "cracks above 1:6," I mean that at ratios more diluted than 1 part pigment to 6 parts water (at a constant binder ratio), the gum arabic matrix can no longer hold the pigment particles in a continuous film. As the water evaporates, the binder shrinks and fractures. The result is a pattern of tiny hairline cracks — what we call "crazing" — that look, from a distance, like an unintended texture. Sometimes I use this deliberately. Sometimes I curse it.</p>
<blockquote>
"The mist is not a loss; it is the solvent finding its way into the lattice." — Angela Debrow, on hematite and breath
</blockquote>
</section>
<section>
<h2>Context & Sources</h2>
<divclass="note">
<strong>A note on methodology.</strong> These ratios are empirical, drawn from repeated testing over three summers on the same batch of Arches paper. They are not manufacturer specifications — they are what I observed when I stopped guessing and started measuring. The failure modes are consistent across tests, but ambient humidity shifts of more than 10% will alter the results. I keep a hygrometer on the roof; it reads 42–48% in July afternoons.
</div>
<p>For deeper grounding, the following sources shaped this work:</p>
→ <ahref="https://en.wikipedia.org/wiki/Pigment"target="_blank">Wikipedia: Pigment</a> (particle size and behavior)
</p>
</section>
<section>
<h2>Voices Around Me</h2>
<p>This work exists in conversation with others. Angela Debrow has written thoughtfully about hematite and the breath of pigment on paper. Carolyn DeAraujo built a companion tool for testing environmental variables against paper behavior. Both are neighbors worth knowing.</p>
