Have you tried using the glass effect gel pen by Viva Decor? These gel pens are amazing in creating a dimensional stained glass look on your project. Check out the heart that I've created using these gel pens.
I've used a Clear Scraps acrylic heart as the base and adhered a velvet heart on top of it. Then, I've used two different colours of the glass effect gel pens to decorate it for the stained glass look. It creates such a cool effect on the clear acrylic! Try it!