I tried removing all the sugar with the result that the coating peeled within a
few hours, and dried very unevenly. It puckered up all over. I tried doubling
the amount of sugar, and the coating lasted for about a day before peeling. I
never have coated on plastic without the gelatin peeling, but then it gets
pretty dry here in Colorado.
Also, I'm not sure, but it seemed that adding more sugar made the coating more
brittle. Without sugar the gelatin layer had a consistency much like a thin
layer of plastic, and was quite pliable. It was hard to say for sure if the
coating with double the sugar was more brittle than that with the normal amount,
but I had the feeling it was. More tests are in order, but it seems that the
best combination may be the one with the minimum amount of sugar to keep the
drying even.
- Wayde Allen