How to Stretch a Saggy Canvas
One of the most common causes of a canvas to become saggy is when it has been stored in an area where it is too humid. This can be due to living in a humid environment, or storing the canvas near an air vent. Humidity can cause the canvas to stretch, which can result in loose, wrinkled and dimpled canvases. It's not the end of the world. This is actually a pretty common thing when transporting stretched canvases from one location to another. You can easily fix this problem to get your stretched canvas back in no time!
Given that it's easier and saves time, many artists these days prefer to buy pre-stretched canvas instead of stretching their own.
Buying a pre-stretched canvas seems fast and easy, but there are countless brands of pre-stretched canvases available with varying levels of quality - one might be better than the other.
There are a variety of differences to be seen when comparing wood stretcher bars depending on the type of canvas and the primer used. These are all factors that have an effect on hanging quality, which contributes to overall painting quality. True quality canvases cost more but are well worth their price. If you purchase a canvas that requires prepping before painting, it's often because they used lower quality materials and you need to stretch the surface in order to make it supple enough for paint. A good economy canvas can work for a professional artist, but it will require some tweaks to the materials and specs of the paint before you can start a painting.
Where to Buy Art Supplies for Painting
If you are looking for products and supplies to use in art projects, be sure to check out our online store. We offer a variety of products including a set of primary colour paint bottles, canvases, paint brushes, and an easel that fits most canvas sizes
The woven material that we call "canvas" is almost always 100% unbleached cotton duck, which shrinks like nobody's business. The "shrink it" method works on any cotton canvas, but works best on canvas that hasn't been painted on yet.
- Then spray very hot water over the back surface of your canvas using a spray bottle. Do not soak
- Work your way through the weave, patting the moisture into it
- Dry with heat, immediately. You can use a hair dryer, prop it up near a hot air vent or wood stove, or set it in a sunbeam on a hot day
|Works very fast||Not a permanent solution|
|Costs nothing||Not the best solution for dimples|
|Not recommended for oil paintings|
|Not recommended for linen|
Even expensive canvas manufacturers recognize that sagging is a common occurrence during transit. They provide "keys" to remedy this, which will have the same effect on even heavy duty canvases that start to sway during transit. What are canvas keys? These are thin pieces of wood or plastic that can be inserted into slots on the stretchers to tighten and support them when you buy a new canvas. If you don't have any of these with your new fabric, buy the number you need separately
- Identify the key slots in each corner
- Fit in two keys per corner
- Gently tap into place with a hammer
|Immediate results||The four corners need to be squared up to maintain 90° angles|
|A long-term fix||Keys can easily come loose during shipping or fall out of place over time|
|Can be adjusted or further tightened after the painting's completion||Not all canvases have key slots|
|Low to no cost|
When all else fails (or when you want to do a permanent fix) you should remove the canvas from the frame, re-stretch it and place it back into the frame. Simple staple art can be created with any stretched canvas (painted or not) as long as there are staples at the back. It's actually a fairly simple operation, but it does require a heavy duty staple gun and staples. Make sure you have an extra pair of hands around if possible (C-clamp or a workbench)
1. Start in the middle of the first stretcher bar then place one staple in the center
2. Tighten the canvas to fashion a loop around the staple, and then press down on it to create a flap-like border along both sides of the first and second bars
3 - Cut the piece across the top, making sure to keep the edge of it and fold in half. Staple the middle of one side, followed by tacking in place all the way down. Continue working from the center of each stretcher bar towards the corners on each side, pulling tight as you go. I would generally advise that you place staples every inch and a half. When you're done stapling, be sure to pull from each side (opposite to the direction of the staple) at the same time for a wrinkle free stretch
4 - The corners are done last. Gently fold tight and staple the corners as many times as necessary to get them to sit flush
|Extremely durable with excellent tension, like a drum||Aligning a painting on a stretcher frame can be tricky|
|The most permanent fix||It'll require a staple gun, some time and space to set up and some physical strength|
|You need to be careful not to pull too hard on your stretcher bars or they might snap|
|Doesn't help much with dimples|
Looking For Art Supplies?
- WHITE BLANK CANVAS: 5/8" Solid wood stretched, 280g Premium Cotton Duck which comes in multiple sizes:
- 18" x 24" (45.72cm x 60.96cm) - SOLD OUT
- 8" x 10" (20.3x25.4cm) - LOW STOCK
- 16" x 20" (40.6cm x 50.8cm) - LOW STOCK
- READY FOR PAINT - Double primed to enhance paint colors - For use with acrylic, water and oil paints - Archival and acid-free, environment friendly
- FAST SHIPPING: Free Shipping=2-5days including tracking number and regular updates of the location of your order
- DID YOU KNOW? 15% of our profit is given to Canadian charities through our partnership with CMHA (Canadian Mental Health Association). Our kits are used by art teacher across the country for their classroom, arts and crafts projects and painting parties