ABOUT GOUACHE:

Gouache paint is similar to watercolour, but it is opaque & a versatile medium. It is often described as an “opaque watercolour”.
Gouache is made up of natural pigment, water and a binding agent (like gum arabic or dextrin).
Gouache can also be used as ‘watercolours’ if diluted with water but will not look very vibrant.
Gouache when mixed with a little and the right amount of water gives a very vibrant, rich and opaque finish to the final painting.
Gouache is thick and dries quickly. However, even if the paint dries, it is easier to re-wet the paint, unlike acrylics, by spraying or adding little drops of water.
When gouache dries it gives a matte finish. It is non-shiny and non-reflective.
The main advantage of gouache is that it can be layered and reworked, unlike watercolours.
If there is a small mistake in the painting, it will be very difficult to correct when using watercolours because of its transparent nature.
However, Gouache, when it dries, becomes opaque and hence it is easier to correct mistakes in gouache paintings as you can layer a darker colour over a lighter colour and vice-versa when using gouache.
The base layer needs to be dry before you apply the next layer of paint.
Gouache, being a versatile medium, works well on any watercolour paper with a fine texture, drawing papers (140 GSM & above), stretched canvas, MDF board, cardboard, wood & toned colour paper.