Canvas’s look great on your walls until the peskiest of warps or slightest of sagging causes it to not sit flush with the wall. Instead, it’s clear every time you look at the print that one end tends to be pushed farther from the wall. Not the perfect display you once had, and it gets more annoying every time you notice it.
Chances are when your canvas changes shape, it’s either an issue with the canvas slacking (as it does naturally over time) or there are dimples forming, or perhaps there’s some damage to the stretcher bars holding the piece together.
Here are 4 Ways to Fix a Warped Canvas Print
- The warm water method
The only thing to be careful with here is that you don’t soak the canvas too much. You only want to moisten the back of the canvas, then using your hand, smooth out the reverse. This is ideal for removing dimples on canvases.
The risk is that if you apply too much water, you can damage the paint/ink pigments. The safest approach for shrinking dimples is to work fast. A quick spray of warm water over the reverse side, then run your hand over the back surface to allow the water beads to penetrate slightly into the canvas, then use a hair dryer to quickly dry the surface.
Always work water onto the reverse of canvas and never the painted or printed areas.
- Applying Canvas Re-Tensioner Spray
There are canvas re-tensioner sprays you can use instead of water. The difference with these is that they include binding agents. So instead of only hot water being worked into the reverse of the canvas then evaporating, the binding agents remain in the stretched canvas, making it longer lasting than just using water alone.
- Working with Canvas Keys
Most stretched canvases come with canvas keys you can use to stretch the canvas whenever it begins to sag or warp. The canvas keys are just little odd shaped pieces of wood. Not all suppliers make it clear that these have a purpose, what that purpose is and how to make the best use of the keys.
To use these for tightening a canvas that’s become slack with time, best practice is first to protect the canvas using thick cardboard because the wood keys will be put into slots on the stretcher bars (in each corner) then tapped into place with a hammer. Don’t be too heavy-handed when working with canvas keys; otherwise, there’s a risk of damaging the canvas or the stretcher bars.
- Re-Stretching Your Entire Canvas
It may not be the canvas that’s warping or slacking, but rather one or more of the stretcher bars used to hold the canvas in place that’s warped. As these are made of wood, if your canvas is displayed in a room with high humidity, there is a risk the stretcher bars can warp. For slight warps, it may be possible to unwarp wood using water and head applied to the opposite side of the wood to try to force it straight again. It’ll be a time-consuming process and isn’t guaranteed to work. If you’re out of options, the safest fix is to gather up supplies, start from scratch and re-stretch the entire piece. This time use quality stretcher bars made with premium woods for strength. These come in different sizes, usually starting around 18mm in thickness. The thicker the stretcher bar, the stronger it will be.
Once you have your stretcher bars, you can carefully remove the canvas from the damaged stretchers by removing the staples. Once you have it off, lay it flat, face down, on a clean and soft surface.
Working on the reverse side, the most important part of getting the location right for the new stretchers is making sure the corners are perfectly matched on the print. If it isn’t lined up exactly, you can find yourself repeating the process multiple times until you get the look you want.
Once you have the corners aligned, use heavy-duty staples to attach the canvas to the new stretcher bars, working one side at a time with the first staple going in the centre. As you rotate the piece to work on each side individually, continually pull the canvas gently to get it taut before stapling.
To Wrap Things Up...
If you notice your canvas is starting to sag a little, the easiest fix is to use the canvas keys that came with your print by gently tapping them into the corners. If you don’t have canvas keys, then apply warm water to the reverse and for longer lasting tightness, use a canvas re-tensioner spray.
If your original stretcher bars have become warped (this can happen when exposed to high humidity/moisture), it may be easier just to re-stretch the canvas, starting from scratch.