I've tried several different brands of photo transfer cloth that you sew in, not iron-on.
The best I've found is made by C Jenkins Company. Unlike other brands it is soft like quilting cotton fabric.
I order 10 white Miracle Fabric sheets at a time; irregulars if they offer them when I'm ordering.
If you wish to do your own, they sell the supplies.
http://www.cjenkinscompany.com