How to Seal Your Background

A well-prepared background will take any amount of paint.

There are many products available for sealing the background of a painting. Your choice will depend on the background surface and the type of paint you are going to use once this surface is sealed. The most common background surfaces in artwork are wood, canvas, board, watercolor paper and card. The most common paints are oils, acrylics, watercolors and egg tempera. Works in pastel and charcoal (which can be brushed with a wash) are also considered paintings.

Things You'll Need

• Low-odor thinners
• Gesso primer
• Gesso powder and rabbit skin size
• Re-touching varnish
• Glaze medium
• P.V.A. adhesive
• Pastel fixative
• Charcoal fixative
• Masking tape
• Paint brush

Instructions

1. Clean the surface you are going to paint. If it is a previously painted surface, scrub it with course wire wool to remove loose paint or varnish. Brush off the debris and, for the application of oil paints, wipe the surface with low-odor thinners. Seal the prepared surface by brushing on a thinned coat of retouching varnish. For virgin surfaces, prime the surface with a mixture of your first color oil paint and low-odor thinners. The lighter the color wash, the more thinner you will mix in solution.

2. Prepare surfaces for painting with acrylics by cleaning and brushing them, then wipe the surface with a damp cloth. For unsealed wood or card surfaces, apply a diluted wash of Gesso primer. For surfaces that require sealing before painting with egg tempera paints, seal them using Gesso powder mixed with rabbit skin size in accordance with the instructions on the Gesso powder tin.

3. Seal very large acrylic works with a thinly diluted P.V.A. (Poly Vinyl Adhesive), which is a cheaper alternative to Gesso. To seal small areas of an acrylic work of art, apply masking tape and brush the edges with a glaze medium to prevent color seepage under the tape. Seal pastel and charcoal work with pastel fixative or a fixative designed for charcoal. Use a spray to avoid smudging or disturbing the chalky nature of these mediums.

4. Select carefully from the available range of high quality watercolor papers when working with watercolors. This is an important first step as areas of virgin white or cream colored paper will eventually form part of the finished painting. Cover these areas by brushing on watercolor masking fluid. This will create a watertight seal between the paper and the watercolors. When the painting is finished, the dried masking fluid can be peeled off to reveal the virgin paper surface. Prepare well and your works of art will last much longer.

Tips & Warnings

• You can buy oil canvases and boards that have previously been sealed with an oil primer at art shops.

References

• Daler Rowney: Products
• Winsor & Newton: The World's Finest Artists' Materials