These pieces of wood behind a painting?

You’ve just bought your new painting canvas. Ready to paint a masterpiece when suddenly you come across 8 small pieces of wood behind your painting.

At the time, I was the first to say to myself, “What the hell is this?

This “trick” is called a chassis wrench, and it’s the key to a beautiful, sturdy chassis that will age well.

What is a frame wrench?

Chassis wrenchesgive your painting an optimally stretched canvas.

In fact, many canvases are slack at the time of purchase, and the use of wrenches will enable the canvases to be correctly tensioned.

A well-stretched canvas will ensure that your painting ages well over time. It is also possible for a canvas to relax over time. This is due to a number of factors, but in particular to changes in temperature over the different seasons and years.

How to stretch a web with keys

You will find below the video demonstration where I show you how to stretch a canvas with the keys. I recommend you watch it.

Here’s how it works:

• Detach the small package containing the various keys (in most cases, you’ll have 8 pieces of wood).
• Place the 8 keys in the slots in each corner of the frame, there are 2 slots per corner (see video).
• Then tap each key lightly with a hammer (two to three light blows per key), move on to the next key and continue cyclically until the canvas is optimally tensioned.
• To check that your canvas is correctly stretched, you can regularly tap it with your finger and listen to the sound it makes.
• Caution: Under no circumstances should you overstretch your canvas, as this would have a detrimental effect on your stretcher and risk twisting your painting.

And here’s the video on how to use the keys on your board.