if this were real stained glass, the lines would all connect within itself, the colors would not spill over the black parts. and the lines wouldn't go beyond, you have many here where the edges aren't neat. it just looks roughly drawn on. further, stained glass has to be divided or it will break. so things like the leaf in the blue, would have an extra line in it. your name is kind of huge and hard to read in there.
ideally i think the lines should be neater, placed over the color, not under. it should be thinner, and be complete, or no one will understand its supposed to be stained glass. right now it looks like a rough cartoon.
---Mike Savad
MikeSavad.com
