How watercolor paint is made
Watercolor is held together by tree sap. The binder is gum arabic, oozed from acacia trees across Africa's Sahel.
- stations
- 6
- things upstream
- 33
- raw sources
- 14
- steps from the ground
- 5
The short version
Watercolor is pigment suspended in gum arabic, the dried sap of acacia trees, with glycerin or honey added so the dried gum stays supple and redissolves. Makers stir pigment into the gum solution to make a paste, then shear it between the rolls of a three-roll mill until the color is evenly dispersed. The paste is filled into metal tubes or dried as cakes in pans.
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Tap the acacia trees
Gum arabic is the dried sap that oozes from the trunks and branches of two acacia species. It is collected from wild trees, mostly in Sudan and across the Sahel from Senegal to Somalia.
about 70% from Sudan
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Dissolve the gum
The hardened gum dissolves readily in water to make a clear, sticky solution. That solubility is the whole trick of watercolor: dried paint softens again the moment a wet brush touches it.
Goes in -
Stir in pigment and softeners
Pigment powder is stirred into the gum solution along with glycerin or honey, which keep the dried binder flexible and quick to redissolve. Ox gall and preservatives may go in too, and the batch ends up as a thick paste.
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Shear it on a roll mill
The paste is fed between three horizontal rolls that turn in opposite directions, each faster than the last. The speed difference shears the paste in each narrow gap and breaks up pigment clumps, and a knife scrapes it off the last roll. Operators may narrow the gaps and repeat the cycle several times.
3 rolls
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Fill the tubes
Most watercolor today is sold in small collapsible metal tubes, as a paste about as thick as toothpaste. The painter thins it with water on the palette.
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Set cakes in pans
For pan colors, paint is set into small open plastic wells and left to dry into a solid cake. Pans come in two standard sizes, full and half.
Goes in
Worth repeating
- The first commercial watercolors were hard resinous blocks that painters had to rub out laboriously in water before they could use them.
- William and Thomas Reeves won a Society of Arts award in 1781 for inventing a moist watercolor cake that dissolved at the touch of a wet brush.
- Gum arabic is also a food additive, used to stabilize soft drinks under the code E414.
Back to the ground
Follow every input upstream and watercolor paint starts as these 14 raw sources.
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Sources
These sources say little about the factory steps themselves, so parts of this line are a general description. Treat the details with care, and tell us if you know better.
Cite this page: "How watercolor paint is made." Assembly Line, 2026-11-03. https://assemblyline.org/make/watercolor-paint