Sublime Stitching's T-shirt Stabilizer makes it easy to embroidery on stretchy t-shirt fabrics with great results. Iron it onto your fabric to prevent stretching while you stitch, then simply tear it away when finished embroidering. (Can also be used topside on dark or difficult fabrics; apply patterns onto the stabilizer instead of the fabric, then tear away when finished.) Packaging includes full instructions.
Sold as one 18" x 20" sheet.