Linda, I've discovered that you don't need to heat set these, but now I know they will go through the wash. Thanks for running that test. Just be sure they are fully dry before washing off the gel. I just wash my pieces with my finger tips in a 9 x 13 cake pan and 2" of water.
Of course, with pressing cloths (muslin) on both sides you can iron the ink dry after applying the gel and after washing off the gel. That way you can proceed faster with your project.