Hints, Tips & Techniques for Designers' Gouache - Mediums

Designers Gouache can be used with water or with water and mediums. Through the use of various mediums the creative potential of Designers Gouache can be enhanced and extended even further. Mediums are additives which alter or enhance the characteristics of the colour. They are used to change the rate of drying, increase gloss, improve flow, provide texture etc.

Layering Colour

Designers Gouache is intended to be applied fairly thickly in comparison to water colour. If diluted with too much water it may 'powder off'. If applied in too many thick layers it may have a tendency to crack, due to the under layers absorbing the water and Gum Arabic from the newly applied paint;  this only becoming apparent when dry. Less layers are definitely best when working with gouache.

Gum Arabic can be added to Designers Gouache when painting in layers to reduce cracking. Gum Arabic should also be added to the colour when airbrushing to ensure that the colour is not over thinned. However the addition of Gum Arabic should be kept to a minimum as it increases brilliancy, gloss and transparency if used in large quantities.

When using a lighter colour over a darker colour, ensure that the lighter colour has a high opacity rating. Avoid using colours over those which are rated as ‘bleeding’ on the colour chart. If you need to overpaint then use Bleedproof White as an in between layer. (see also under Whites). 

Thicker colour/adding texture

If you want to apply colours more thickly try using Winsor & Newton Aquapasto, a semi transparent gel medium which allows you to build up relatively thicker layers without fear of cracking or flaking when dry. Aquapasto also helps the colour go further and increases its transparency. For increased texture use Texture Medium which contains fine particles and can be used to give the impression of depth and structure to paintings, it is ideal for emphasising areas such as sandy beaches or the bark of a tree in figurative paintings.

Improving Flow

Water Colour Medium has the same characteristics as Gum Arabic, but also increases the wetting of the paper which will improve the flow of washes across the surface of the paper.  (Caution: Water Colour Medium should not be used with acid sensitive colours namely those containing Ultramarine.) Alternatively Ox Gall liquid is a wetting agent and can be used to improve flow when mixed directly with Designers Gouache.

Slow drying

Blending Medium is used to slow the drying rate of Designers Gouache allowing you more time for blending. It is particularly useful in hot climates where artists would like their colours to stay open and workable for longer periods of time.

Lifting Colour – making corrections

Lifting Preparation allows dry washes, including staining colours, to be more easily lifted from paper with a wet brush or sponge. It is an ideal preparation with which beginners can prime the paper allowing corrections to be made more easily to their painting.

Resistance to water

Acrylic Matt Medium can be used to achieve water resistance – however care should be taken with the amount used as some colours can react and change colour or consistency. The addition of matt medium will also deepen the tone and reduce the matt finish – so always try a small area first.

Using Designers Gouache in conjunction with other water based media

Designers Gouache, Artists' Water Colour and Cotman Water Colour can be fully intermixed. Although Designers Gouache can be mixed with Artists’ Acrylic and Galeria, care should be taken as some colours can react.

The pinks and violets in Designers Gouache can have a tendency to change colour on combination with acrylic. Some other Designers Gouache colours may also be sensitive to alkali and produce gelatinous or lumpy mixtures. All combinations should be tested on the palette prior to use.