Online Magazine
Why do you need your Wooden Wedges?

Why do you need your Wooden Wedges?

Why do you need your Wooden Wedges?

How do wood wedges work?

You’ve recently bought a stretched canvas and you are asking yourself what the small plastic bag on the back should be used for.What do we do with these small triangles?

A lot of people ask the question, but what are they used for? It can seem like a mystery. Here is the answer:

Why do you need your Wooden Wedges?
What is in the bag?

The bag contains 8 (or more) small triangular pieces of wood. The wooden wedges are used to adjust the tightness of the canvas.
You should know that stretched canvases are not really « finished ». They must be tightened after painting.

Why do you need your Wooden Wedges?

How does a stretched canvas work?

A stretched canvas is composed of stretcher frames and bars, and all material is assembled with strength in each corner.
If you look closely, canvas wedges have notches in the corners. A corner will have 2 wedges that will be used to make it tighter.

Why stretch a canvas?

Whilst painting, the artist gradually burdens the canvas with the addition of paint, materials and collages. Over time these changes can affect the tightness of canvases. Do not also forget that the canvas of a painting is also subject to room temperature changes. These changes can be caused by sunlight, humidity, or cold and they affect the fibers of the canvas. As the canvas becomes heavier it can move and loosen. That’s why this bag of wedges is quite useful!

Why do you need your Wooden Wedges?

How do I use wedges for tightening?

Step by step:

  • Using your fingers, insert the wedge into each of the slots (pointing down and long side parallel to the frame).
  • With a hammer, gently tap the flat part of the wedge. It is important not to hit too hard so you don’t cause damage to the frame. The wedge will then stretch the space between the two bars of the frame and stretch the canvas.
  • Repeat on all corners (+ bars for large canvases).
Why do you need your Wooden Wedges?
Why do you need your Wooden Wedges?

Tip #1: check the tightening of the canvas after each wedge position. You should stop as soon as the fabric is tight enough; because the embedded wedge cannot be removed once it is inserted and can create too much pressure. The wedges should be used carefully and not stretch the fabric too tight, to avoid too much tension, which could twist or damage the frame.

Why do you need your Wooden Wedges?
Tip #2: Some wedges have points that are very sharp and thin. This can tear the fabric. I advise that you cut this wedge if it is too sharp (see the picture below).

Why do you need your Wooden Wedges?
How to tell if the fabric is too tight?

Once your paint dries completely (with your varnish) do a little flick with your fingers at the center of your canvas.

  • The canvas vibrates like a drum membrane while remaining in place = good tightening.
  • The canvas seems soft and doesn’t vibrate = low tightening.

How to choose a stretched canvas?

Some brands are already well stretched. You should, however keep the wedges for future use because the fabric tightening may change.

  • Cheap canvases may have faults and no wedges, or have very poor tightening. Paintings without wedges are more difficult to recover, especially if the frame is glued together.
  • With small sized paintings (6’’x6” or 8’’x8’’) it’s not always necessary to use wedges.

The canvas that I personally use:

I usually use wedges after my painting is finished (painted and varnished, completely dry).
I only use primed linen canvas on wooden frames. Here are some recommendations of brands that you may find helpful:

For those who prefer linen canvas, natural, and coated with a transparent primer: Honsell Natural Linen Canvas is a good choice.


Information for this article was provided by professional fine artist, Amylee Paris. You can visit her colourful portfolio or follow her on Facebook and Instagram

Find all Amylee’s posts published in GreatArt online Magazine by clicking here!


GreatArt – your art superstore

Art supplies, ideas and advice for all techniques.

GreatArt offers you art supplies for all techniques from:

  • traditional fine art painting,
  • drawing,
  • sculpture,
  • printmaking,
  • graphic art,
  • illustration,
  • airbrushing,
  • model making…

We offer an extensive range of stretched canvas and display products for exhibition, all the art supplies required to create your own bespoke canvases, as well as custom framing and mounting services from GreatArt Store. You’ll also find hundreds of articles and tutorials to browse in the online magazine.

Louise from GreatArt

Voir plus d'articles

2 comments

This site uses Akismet to reduce spam. Learn how your comment data is processed.

  • I found this instruction on canvas tightening really helpful as I always used my wedges before
    painting my canvas and always thought it did not really tighten the canvas enough.

  • Thanks for this useful article. I didn’t really know how to insert the wedges correctly or when to use them.