Select a shadow box picture frame about the same length as the shirt. Shadow box picture frames are deeper and have more room to accommodate the fabric of a shirt.
Cut the heavy fabric matting to fit inside the body of the T-shirt. Choose a high-quality matting that will support the weight of the shirt.
Punch holes around the edge of the matting using a tack. Make two holes side-by-side that are about 4 inches apart all the way around the board.
Insert the matting into the T-shirt. If you want the front of the shirt to face forward, cut the matting out of the neckline so you can't see it. If the T-shirt's back faces out, the matting won't be visible.
Sew along the edge of the fabric through the T-shirt and board, everywhere there are two holes together. Use a high-quality thread, like quilting thread, and tie a tight knot when you are finished. Choose thread that matches the fabric.
Insert the mat into the shadow box and close it. It is now ready to hang.