Mediums and Surfaces

Acrylic paints are water based with properties similar to both watercolour and oil paints. They are made from pigments suspended in an acrylic resin which is formed by combining acrylic and methacrylic acids. This produces a medium that dries quickly with a clear film allowing light to penetrate and reflect the pigment particles. With exceptional light-fastness acrylic is ideal for building up layers of glazes.

Charcoal and charcoal pencils are often used for life-study drawings by allowing a dramatic range of textures and shading to be created.

Gouache is a water-based paint with ingredients similar to watercolour but with added white pigments to give a special opacity and brilliance.

     Mixed Media

One or more combinations of media to create the artwork, e.g. pastel and watercolour.

Oil paints are pigments traditionally mixed with linseed oil that hardens after application. Recently, water mixable oil paints have been developed that do not require solvents. Traditional oil paints mainly differ from acrylics in their drying times, being slow, and their less clear propagation of light. This property gives oil paints a particular ‘look’ which is not achieved with acrylics. Oil paints are subject to yellowing, cracking and brittleness over time although careful restoration can revive and protect a painting.

Soft pastels are made from pigment mixed with chalk, gum and a preservative. Pastels produce a purity of colour that is thought to be the closest possible to the colour of the pigment while using a minimum of medium.

Inks vary in their opacity, light-fastness, and permanency. Spirit or shellac based ‘permanent’ inks are water-resistant or water-proof but the colour may be fugitive. Many artists’ inks are only suitable for particular pens.

The familiar graphite pencil is available in up to 20 grades of hardness and softness. It is used by artists for drawing and sketching and is easily erasable.  Coloured pencils have been gaining in popularity with artists and exist in three main types: crayon, pastel and aquarelle.

Pigment

Pigments are the colour sources for paints. Natural pigments are either organic from animal (e.g. ivory black), vegetable (e.g. madder root) or synthetic sources (e.g. Alizarin crimson), or inorganic which include minerals (e.g. cadmium yellow, cobalt blue) and natural earths (e.g. raw umber, Venetian red).

This is one of the oldest mediums and can be found in the 18,000 year old cave paintings in the Dordogne, France. The pigments are much the same as those used in oil paints with a binder of gum Arabic, a glycerine moisturiser and ox-gall as a wetting agent. The transparency of watercolour can be rendered opaque with the addition of Chinese white.

Canvas

The best fabric for artists’ canvas is linen as it is strong and retains its natural oils but it is expensive. Cotton is widely used because of cost but although it stretches more tightly over its wooden support it is inferior to linen in strength and longevity. Thus it should not be used for works designed for a long life-time as the cotton can become brittle especially if not properly prepared. Synthetic fibres are also used and polypropylene canvas is ideal for some digital printing.

This is made by laminating canvas onto a backing board but is not really suitable for permanent work.

Ingres papers come in a range of colours and are particularly used for pastels, crayons or pencils because of their rough texture.

         Paper

Cartridge paper is most suitable for pencil drawings and charcoal. It is available acid-free which extends the life of the work.

Watercolour paper has surface finishes varying from Rough, NOT (cold-pressed) which is less rough to Hot-Pressed which is smooth. Most are acid-free.

Vellum is a fine parchment suitable for calligraphy.

       Sand Paper

Sand paper  is chosen for pastel because of its ‘tooth’ and texture presenting and ideal surface for the pastel to grip onto and enable better layering.

Wood panels may be used for oil painting but are rather heavy and inflexible. Otherwise they are most suited to traditional tempera – pigments mixed with egg-yolk or some other size. Both plywood and hardboard panels are suitable surfaces for work-trials prior  to canvas if carefully prepared.