Western Red Cedar is the definitely the choice timber to make artist stretcher frames with.
It is stable, light, resists mold, moisture and insect infestation.
Chapman & Bailey produce mitre shouldered mortise and tenon jointed cedar stretchers that use timber wedges to expand the corners and braces connections.
They produce cedar stretchers in 4 different profiles, starting with “Light Weight” at 19mm x 45mm for small canvases then moving up to PQ (professional quality) 22 x 67mm, ideal up to 137mm. The next size being Gallery which is 32 x 67mm and these have tenons and wedges that are 7.5mm thick, an important exclusive design feature of Chapman & Bailey’s. The weakest element in cedar stretchers is the softness of the tenons and there tendency to flex. On larger size canvases this weakness causes the stretcher arm to slightly rotate at the corner under the tension created by stretching the canvas. Increasing tenon size to 7.5mm firms the corner and stops the rotation at the corners.
The 7.5mm extra large wedges that bear against the full width of the shoulder enable easy tensioning of the stretched canvas.
For extremely strong and stable stretchers Chapman & Bailey recommend using their Cedar Museum Stretcher. Its profile size is 40 mm x 80mm and its angle of bevel dropping down away from the canvas at 15% keeps the canvas well away from the inside of the stretcher arm, i.e. never any rub lines.The museum stretcher also uses 7.5mm thick tenons.
The cedar used by Chapman & Bailey is sourced from sustainably managed Canadian forests.