I have used both aloe vera & Delta Textile Medium. Delta says not to wash the fabric for 7 days so I set it aside and have yet to wash it since inking it & painting on the textile medium so I can't comment on which one washes better, but I've heard that medium holds the ink in better so that's why I'm trying it.
I will say that it is MUCH stickier than aloe. It also dries stiffer before washing. It does seem to bring out the color more than the aloe so far. I'll keep you posted as my experiment continues. I bought the Delta textile medium at Hobby Lobby.