Sold as a single tube, so you can buy the colours you actually need.Holbeins series letter reflects pigment cost, not quality. Series C is the specialty colours.

Pigment, lightfastness and series as published by Holbein. Holbein does not publish an opacity rating for individual colours; the range as a whole is described by Holbein as opaque.

Acrylic Gouache, Not Traditional Gouache

Why Holbein Acrylic Gouache Is in Serious Studios

Getting the Most Out of This Tube

Straight from the tube is the default. This is what Holbein designed it for, and it is where you get those even, flat, uniform layers. Add a little water to loosen it, but go easy: very diluted washes can dry streaky across a large flat area, so build coverage in thin even coats rather than flooding it on.

Watch the palette, not the clock. Holbein gives an open time of roughly 10 to 30 minutes and notes the drying time is much like ordinary watercolour. The practical consequence is that paint left sitting on the palette will go off and will not come back, so squeeze out small amounts as you need them.

It plays well with acrylic mediums. Holbein states the range is compatible with all acrylic mediums, so you can change the body or extend the working time if you want to. Soft synthetic brushes suit it, since they hold enough paint to lay a flat area without dragging.

Does Holbein Acrylic Gouache reactivate with water once dry?

No. Holbein describes it as water resistant once dry, specifically so you can paint layer upon layer, which is the main practical difference from traditional gum arabic gouache. Note that Holbein says water resistant rather than waterproof, and very thin, heavily diluted passages can still be disturbed if you scrub at them with a wet brush.