A support is whatever material onto which the paint of an artwork, including the primer, is applied. Slate, marble, copper, aluminium, glass and paper have all been used with some success as supports for oil paint, but many of these require unusual preparation and conservation. For the last 500 years the most commonly used materials have been wood and canvas. The first artists to develop the addition of drying oils to paint simply continued to make their habitual wood panels- in Italy using the easily available but rather unstable poplar, in Northern Europe using the heavier but more durable oak. As the Renaissance continued so did the demand for ever larger works which had to be transported further afield. Obviously in these cases wood was inconvenient and expensive.
Temporary decorative works had long been executed on linen, a cloth made from fibres derived from flax plants. It was gradually accepted that linen could support paint permanently. In a city like Venice good quality linen was manufactured for sail-canvas, and by the end of the 16th century this material was a common support throughout Southern Europe. In the 19th century cotton duck became available as a cheaper, stretchier and generally inferior alternative.
In the 20th century the increasing scarcity and expense of seasoned hardwood timber has been met by the appearance of various kinds of reconstituted wooden boards: masonite, presdwood, masonite, hardboard and latterly, Medium Density Fibreboard, most of which have proved suitable substitutes.
Generally speaking a good support should have, to some extent, three characteristics:
- Absorbency: it should microscopically draw in a slight amount of the liquid binder of the paint.
- Tooth: it should have slightly pitted surface which allows the binder, when dry, to lock into it.
- Stability: it should be subject to no more movement than, in dried state, the paint it supports.
Clearly, metal, glass and most stone can be given tooth have no absorbency. Wood and canvas have both of these characteristics naturally, to the point where their absorbency has to be diminished by subsequent preparation. But if badly chosen, cradled or stretched, or kept in hostile surroundings, neither of these may be stable enough to avoid moving the paint layers to the point of wrinkling or cracking them. There is, in a sense, no perfect support material.
In choosing a support, think about the quality of the paint surface intended in the work. Art shops usually sell unprimed linen in a range of sizes of weave. Whilst very precise handling of paint might seem to need the finest “portrait” grade, many painters working on a large scale or with impasto would prefer the coarser ones. If the wobble of a stretched canvas is objectionable, then consider using wood, but remember that it is now difficult to obtain hardboard or MDF in some of the larger sizes. The traditional recourse for wood panels was to piece together several smaller pieces together on a rear framework (“ cradling”), and then to bridge the surface joins by glueing on canvas in strips or all over the surface (“marouflaging”). This work can take some time.