i finally had an opportunity to try out "FabTac" stencil material for painting on an awning. i thought i'd share my experience.
FabTac is a paint mask material, cuts like sandblast or other 5ml materials, and is specially formulated to adhere to Sunbrella and other sythetic canvas awning materials.
the material cuts and weeds well (it is thick, so i had to beef up the cutting pressure), but i didn't use it for any tiny lettering. (the smallest letters were 2" Palatino Bold, and it worked fine). the awning was on-site (not flat material in the shop), and I was able to adhere the stencil with a squeegee and with a piece of 1/8" acryllic behind the awning. you have to have something flat and hard to push down onto.
i applied 2 or three coats of Deka (water based acryllic sign enamel) paints. The Deka dried so quickly that by the time i finished the first coat and had a drink of water I was able to go back and do the second coat. I'm not sure how it would have worked if i'd been using 1-Shot and had to wait longer for it to dry.
I did two sign of 3' x 3' on two ends of the awning. the first one was a little shakey (but acceptable) because i didn't realize how important it was to use the acryllic board for a backer. the second panel came out great, with only a tiny bit of clean-up needed. (i just painted over the goofs with a color that matched the awning fabric).
so, my experience is that somebody with only a casual knowledge of painting technique could produce acceptable lettering efficiently on an existing awning. my only complaint is that FabTac is only sold by Astrup, and their customer service has something to be desired. FabTac, including shipping, costs about $50 for a 20 yard roll x 17" wide (18", with 1/2" of perf on both sides).
