How do Gouache and Acrylic in water colour technique differ from real water colour?
Gouache is an opaque water colour, made with Gum Arabic it is matt, flat and opaque because it is extremely highly pigmented. Gum arabic is far superior in flow properties in comparison to acrylic. Gouache is most suited to more solid colour effects as opposed to the gentle pale washes of water colour. Acrylic is time consuming because you have to thin it so much and it dries waterproof, quickly ruining sable brushes.