I read in another post that you could use extract or vodka with gel to write on fondant and gum paste. By extract, do they mean like vanilla extract, etc., or something else? Also, some people say that the writing pens work great and others say they don't work at all. Makes me think there must be something different one side is doing differently than the other. Does the gum paste or fondant need to be fully dry, or is there another trick to it? I need to do some labels and bar codes and want to find the best way before I start working on them.
I use vodka to mix. Also use pens and are OK, no great simply OK, quick but not precise as a brush can be. Always paint while still fresh, although don't know really why LOL!
Wouldn't the bar codes be easier if you cut thin slices of black? Just an idea...
On things that will definitely not be eaten, I use crayola markers. The fine-points work really well on dry gumpaste, not just for writing words, but for adding details like eyes on figures and stuff like that.
On things that will be eaten, I mix gel color with vodka and use a script liner paintbrush. It works fine to mix with vanilla extract, if you don't want to use vodka. If you're going to do a lot of painting, vodka is much cheaper in the long run.
I have mixed my gels with pure extracts like vanilla or lemon. Just thin it down a little bit, like a drop at a time until you get the correct consistency. For me, the consistency which works best would be almost dry brush. I use food only brushes, a small bowl, a drop or two of extract on on side and the gels on the other and keep working until I get what I need. I use some folded paper towel to get it try enough.
If you go through my photos and see some writing on cakes in black, Poker Cake, God Bless Antinonino, they have been written on free hand with brushes.
Another example is the Dora the Explorer cake where I used fondant for one of the first times. (I really didn't like the way that cake turned out, the food gel was too runny)
Hope this helps,
Book Title (book is only about 1 1/4 inches tall!)
Poker Cake: Suites on Cards, Greeting and chip details in gels
I used vodka, but now I am thinking lemon extract, because I could smell vodka on one of the cakes in the past.