I’m now going to detail how to get the fusible interfacing onto the shirts.
The first thing you want to do is cut out twelve rectangles of interfacing. I made a cut every 16 inches, using a 16 x 16 square ruler. You want the inferfacing to be larger than the 12.5 x 12.5 squares you’re going to eventually cut out of the t-shirts.
Next, it’s time to cut the shirts in two. Decide if you’re going to use the front or back of each shirt. Then, cut up the sides. You’ won’t need the sleeves.
The picture above shows a shirt that has been cut in two pieces. I used the front of this shirt, so I cut it with the sleeves still attached to the back piece. I can use the back fabric for other projects.
Once you have pieces of interfacing and pieces of shirts, it’s time to fuse them together. I found it very helpful when making this quilt top to use a pressing cloth. Often, the iron didn’t want to glide over the t-shirt fabric, so the pressing cloth really helped.
Before you fuse the interfacing and the shirts, you need to find out which way they stretch. You want to put the interfacing on the back of the shirts, but in the opposite direction that the shirts stretch. For example, if a shirt stretches vertically, you want the interfacing placed so that it stretches in a horizontal direction. This way, they will keep each other from stretching.
Once everything is placed correctly, use your iron to fuse the interfacing to the back of each t-shirt piece.
Above is a picture of a shirt piece with interfacing fused to the back. You can see the design of the shirt on the front. If you look in the upper right corner of the shirt, you can see that the interfacing extends beyond the shirt. That’s fine. You want to make sure that a large portion of the shirt has interfacing, to make it easier for you to cut a 12.5 x 12.5 square for the quilt. If the interfacing didn’t cover so much, it would be harder to center the cut square around the design you want.