Once, after I dry cleaned a wool coat that I had tailored by hand, it was returned with bumps, waves, and ridges. While the wool fashion fabric didn't shrink, the hair-canvas did, causing great inner conflict in both the coat, and in me. I didn’t know that the materials used inside the coat were supposed to be pre-shrunk as well. This was a difficult lesson to learn.
This blog post will provide a visual example of why you should pre-shrink your hair canvas. Look at the squares below. They start off with the same exact measurement of 5“ x 5“.
Then, I soaked the left one in cold water. The cold water shrunk the hair-canvas along the cross-grain by half-an-inch! That's a 10% shrinkage! Surprisingly, the grain line remained intact, and didn't shrink with cold water....
The method I use to shrink hair-canvas is the, "quick-soak and abusive-steam method."
First, soak the hair-canvas in cold water for 5 minutes. Then, steam the hair-canvas with a hot iron, until it is completely dry. Now let's look at the results.
This time, even the grain-line shrunk by a quarter-inch as a result of the high heat.
Some traditional tailors will soak hair-canvas overnight, in cold water, then air dry it. I'm not sure if my method, above, will completely eliminate the shrink potential of your hair-canvas. If you are unsure, use the more involved traditional method. Or, even better, soak overnight, then steam-dry with a hot iron.
If you don't shrink your canvas, your garment could initially look fantastic, but the moment it rains, or your coat encounters hot steam at the dry cleaners, your garment may become unwearable, because the canvas will pull on and distort your fashion fabric. To avoid wasted time and heartache, take a couple of moments and soak your canvas. (This is also a reminder to pre-shrink the other materials you will be using, like the interlining and the lining fabric, too!)
Pre-shrinking canvas will help you create long-lasting, beautiful garments for decades to come.