I learned glass gilding from Bendon Brandon at the SOG (Society of Gilders) event held in Lancaster, Pa a few years ago, so I am far from an expert and have only actually done it about 4 times total (on glass).
The job was done Boston Style, with outlines and matte centers, both of which were done through paintmask, to help with speed and accuracy. It would take me a few hours to outline the simple line of copy due to my lack of experience. Anyway, I learned the hard way about quick drying soft Fine Gold's Back-up, pulling up with the vinyl mask, I had to just about re-outline the whole thing again freehand. Lesson learned, outline was not faster, done with paintmask, but matte centers (really hard to see) came out great!
Possibly next time I will use Japan color to outline? Any input guys?
After that fiasco, I used my old gelatin capsulesand a little detergent in filtered water (worked well in test) with a spray bottle (thanks guys for that tip!), prepped according to LeBlanc's book and with my trust old tip and lots of loose gold, I gilded away into the night. The first gild was a little rough to start, but smoothed out toward the end. I found that re-floating the gold is more difficult with the spray bottle than the water size brush I used in the past, but it still came out ok (just with lots more holidays). I let the first gild sit over night and all the next day (I have a day job), I rubbed it down to find lots of holidays, and laid the second gild with just the 2 geletin capsules in water and no detergent which went a lot easier. Again, I let that sit over night. The next day, I rubbed that down and I backed it up with Fine Gold's Back-up enamel and cleaned off the excess gold with cotton and water. I am not a pro, so it looks great from 5 ft away and even better from across the street
Denver Chapter of the Letterheads