How to Prime Unprimed Canvas for Painting
Some artists may prefer to buy unprimed canvas because some impastos tend to adhere to raw canvas more effectively, or it may be that canvas with particular type of weave is only available to them in the unprimed form. In such situations the artist may be required to prime there own canvas.
Preparing a canvas to be painted on is known by artists as 'grounding'. The most common type of grounding primer is 'gesso', this was traditionally made from animal parts and is also known as 'rabbit-glue'. Some artists use emulsion paint as a primer, however, this is frowned upon in the art world.
Oils or acrylic paints will adhere to almost any surface, but it is important to remember that the paint will only be as good as the foundation that you lay for it. If you apply a coat of gesso and you find that it is beading up then you probably have a surface that is dirty or is not compatible with the primer. Cleaning the material with mineral turpentine, mentholated spirits or sanding the surface lightly; and using a coat of clear sealer, may prevent this from happening.