im wanting to make stained glass using gelatin but I need to know what I can use to make the outline of the image im using that will still be flexable enough to maintain its design without cracking? any ideas would be helpful.

There is a great tutorial on YouTube from Global Sugar Art on Crystal Flowers. Gelatin is used to make the flowers. They can be colored and are very flexible. 

Here is the link for the tutorial: 

You could essentially use the same idea, but make your stained glass effect instead. 

AYou could use sugar veil that is colored black for outlines.

thank you so much, I hadn't thought of that. always wanted  to purchase sugar veil and try it.  I appreciate the tip, thanks again.