I make a variety of double crusted (top and bottom) savory pies. For ages I used various spices on the top of the pies to indicate what they were, but that system is starting to not work and I'm looking for another solution. I'm familiar with Pierolglyphics from Aus / NZ where hole patterns are cut, but would prefer to not use it. For a while, there was a pie company in NY called Pie Face - they drew cute little faces on their pies to mark their flavors with a piping bag. While I don't want to use faces, I would like to find a way to write / draw on the pies. Does anyone know what they used or know of something that would work? I've heard they use Blackjack Caramel color, but i can't find a source for it in bulk and wonder if it's a Aus/NZ thing only. Baring that, I'm open to suggestions. Pies bake around 400F for 20 minutes. Thanks in advance.