I’ve done lots of hand embroidery on flour sack towels using both no interfacing and a tacky wash away type interfacing. I preferred not to use the tacky interfacing as it made my needle gummy and I had to constantly wipe the needle with alcohol to remove it. Ugh! The embroidery and the towels have held up well. I washed the towels first, not sure if you can do that with yours, to eliminate shrinkage or at least lessen the possibility. My towels are used often. Not sure if this is helpful.