24th Oct 2023

Stretchers & Stretched Canvas

What is a stretcher?
A stretcher is an expandable timber frame on to which works on canvas, linen and fabric can be attached and held taut. Timber wedges, called ‘keys’, are tapped into slots in the interior corners to expand the stretcher. This means the stretcher can be keyed out to accommodate changes in the canvas that can occur over time. City Art Depot manufactures made-to-measure adjustable cedar stretchers using the traditional wedge system. They are stable, lightweight and easy to assemble and can be made to different thicknesses and dimensions with or without crossbars.

What is the difference between a stretcher and a strainer?
A strainer is a rigid frame with fixed corners for stretching paintings. As the corners are fixed together, there is no way to expand the frame to tension the artwork should it slacken or ripple. Strainers are however a common and cost-effective alternative to stretchers. City Art Depot manufactures pine strainers for small to medium works on canvas.

Why choose a City Art Depot stretcher?
City Art Depot cedar stretchers are popular with artists, art galleries and museums across the country. They are made to measure using the traditional wedge system for tensioning a painting. We start each stretcher from rough-sawn 75 x 50 mm cedar. We straighten, profile and mortice-and-tenon each corner accurately and provide wedge slots. Cedar is chosen for its stability and light weight. Although cheaper, pine is not suitable as it is heavy and can be unstable.

What do the wedges do?
The wedge system is the superior method of applying the required tension as each corner can be stretched in both directions separately. City Art Depot wedges are made from hardwoods and are large, making the tapping out easy and accurate. Being from hardwood, they do not split. Our crossbars are also expandable in the same way.

Can you stretch an existing artwork on to a new stretcher?
Yes. If the work is in good condition, we can measure the painting, make the stretcher to size, staple the painting into position and adjust the tension to suit using the wedges. Artworks painted on unstretched canvas can be successfully stretched. City Art Depot manufactures stretchers for conservators across New Zealand who re-stretch collection paintings, so assisting in the long-term stability of the artwork.

Can I frame my canvas artwork without a stretcher?
Some paintings on canvas are painted unstretched and as part of their design should be left this way. City Art Depot can frame these behind glass or by attaching the canvas to the face of another piece of stretched canvas so it overhangs the edges.

Why is my canvas rippled?
With changes in heat and humidity and the effects of gravity, works on canvas can expand, contract, warp or sag. This slackening causes the tension to be lost across the surface which in turn can lead to the paint cracking and the canvas distorting. By using a stretcher, the artwork can be keyed to correct these defects. Canvases rolled in transit can also present ripples or folds when unrolled. City Art Depot staff are able to examine your canvas and give you the best option going forward with your artwork.

Can you clean a dirty painting?
Old unglazed paintings on canvas accumulate dust, fly dirt and grime over years, changing the colour and character of the work. At City Art Depot we advise clients against trying to clean a painting themselves. Cleaning and repairing should always be handled by a qualified art conservator. City Art Depot can inspect your artwork and arrange a paintings conservator to perform remedial work.

How do you stretch a large painting?
Large paintings are best stretched on to an adjustable stretcher. Cross bars in the stretcher allow for strength, support and adjustability.

How much does it cost to get a painting stretched?
The cost of stretching a painting is calculated based on the amount of timber required and the time taken to manufacture the stretcher and stretch the artwork. City Art Depot staff can provide quotes for stretching canvases in our shop at 96 Disraeli Street, Christchurch.

Should a painting on stretched canvas be framed?
Frames protect paintings from physical damage. As works on canvas most often do not require glazing, a stretched canvas may be framed either with a rebated frame (covering the edges of the artwork) or in a shadow frame (sitting around the artwork). City Art Depot makes custom frames to perfectly fit the artwork within.

Get in touch with our team to discuss our stretchers or stretching your artwork.