How paint is made

Latex wall paint is white pigment and plastic glue floated in water, and it sets as the water leaves.

stations: 6
things upstream: 60
raw sources: 21
steps from the ground: 9

The short version

Water-based paint starts with a mill-base: water, glycol, dispersants and defoamer premixed for five minutes, then loaded with titanium dioxide and extenders under a high-speed blade. Meanwhile resin is stirred with thickener in a larger let-down vat for about 30 minutes. The mill-base is pumped in, the batch is adjusted against lab tests, and it goes to cans.

Premix the liquids

Water, propylene glycol, surfactants, dispersants, defoamer and biocide are measured into a dispersion vat and stirred for about five minutes. This is the start of the mill-base.

Goes in
Water
Load and disperse pigment

With the disperser running, titanium dioxide and extenders such as calcite, talc and barytes go in a set order. Blade speed climbs as the load grows, and shear breaks clumps of pigment so resin and additives can wet every particle.

Goes in
Titanium dioxide Pigment
Prepare the let-down

In a larger vat, the emulsion resin is mixed with defoamer, thickener and coalescent solvent for about 30 minutes. The resin is the part that later forms the film.

Goes in
Acrylic
Pump in the mill-base

The finished mill-base flows into the let-down while hydraulic mixers keep everything moving. The nearly complete paint is stirred for another 30 minutes before the last thickeners and additives go in.
Test and adjust

The lab samples the batch for viscosity, density, hiding power, gloss and dry time. The batch may be fine tuned and mixed again, and tinted lines also get checked for color strength.
Fill the cans

Approved batches go to canning. Two samples are taken here: one kept in case it is needed later, and one for final inspection.

Goes in
Tin can

End of the linePaint Next it goes into refrigerator, microwave oven, washing machine and 41 more.

Worth repeating

Interior walls at the Ness of Brodgar, which are 5,000 years old, include stones painted in yellows, reds and oranges using ochre pigment.
In 1718 an English inventor patented a machine for grinding colors and claimed that paint ground in his horse-driven mill went more than twice as far as paint ground any other way.