Confectioner's glaze is technically edible, but it's basically a type of shellac, as I understand it. I have two types and they both have very cryptic ingredients listed on the bottles.
One says "food grade refined bleached lacquer" and the other says "50% candy glaze, 50% grain alcohol." Woo hoo!
It does smell horrible, too, which wouldn't make me want to eat it, even though the stench does dissipate after a while.
If you've colored the petals with food coloring let them dry, then dip them into the glaze.
Make sure that the petals aren't touching each other while they're drying, because they'll stick together and be difficult to separate.
Kara Buntin owns A Cake To Remember LLC, custom wedding cakes in Richmond VA