I am using stix-it with my polyester material (Koverall material) and you will find out that when you apply heat to your fabric using your iron the material will be very smooth. The raised fibers on the balsa seem to just vanish. I am covering a 4 * 60 right now using Stix-it and the polyester material is coming out very smooth.

I am sealing the fabric using Nitrate dope. Two or three coats seems to be just right. I am then going to use Rustoleum spray paint to paint my 4 * 60. Rustoleum is full proof up to 15% nitro fuel.. I have tested 4 different types of Rustoleum and all 4 types where fuel proof using 15% fuel.

I have chosen to us Rustoleum because of the ease of use and of all the colors avalible. I am painting mine as a German ME-109f in desert camoflage.

I hope this helps