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Anatomy of a Painting

Paintings conservators consider paintings as layered structures.  Identification and characterization of all the component layers of a painting is the essence of the examination process.  This analysis informs treatment possibilities and is critical to the work’s long-term preservation.

Support Layers

The primary support refers to the image-bearing surface (e.g. canvas, wood panel) but there may also be an auxiliary support which in turn supports or strengthens the primary support (e.g. stretcher, strainer, wood battens).

Stretcher or Strainer – the wood frame over which a painting on canvas is stretched and fastened through the foldover edge (margins), typically using tacks or staples.  A strainer has fixed joins whereas the joins of a stretcher are designed to allow for expansion so that tension in the canvas may be increased.

Canvas  – the textile support on which the image is painted; cotton “duck” canvas and plain weave linen canvas are  most commonly used.  Some artists paint on textiles that were not intended for artistic purposes. A variety of weave types, fabric weights, and fibre types (linen, cotton, etc.) are possible.

Unorthodox supports may be utilized by artists, often for economic reasons. The reverse of an early work by Alberta artist Alex Janvier, RCA is shown here before treatment. The primary support was a finely woven cotton textile glued over an auxiliary support of corrugated cardboard cut from a 1950’s “Wagon Wheels” box. The painting was restretched over a rigid, inert support, but the cardboard was retained for owner Jackie Bugera, Bearclaw Gallery, Edmonton

The keyed stretcher with mortise and tenon joins shown above is a common type. Two keys in each corner allow for independent movement of the stretcher bars; each key may be tapped to open the join slightly, tightening the canvas. Keying out of a stretcher is best undertaken by a conservator to ensure damage does not occur.