Me, when I put the tissue on, I use 50/50 water and Elmer's white glue to attach the tissue to the frame. Spray with water spiked with a little alcohol to aid drying. Then, I give it a good coat of clear acrylic that can be found at my local paint shop. Then paint on over that. Works really well, and I don't like messing with success!
I have only used enamel in the form of enamel paint, so as a dope substitute I have no idea. But I am sure it might work. If you don't like it, rip it off and go again.