Step One: Testing This was the first time I tried this, so I tested the products on a piece of glass. I simply took the glass out of a picture frame, washed it, and went to work. The glass wasn't ruined; when I was done practicing and it had dried, everything peeled off, and I could easily scrape any residue off with a razor blade and put the glass back in the picture frame.
Step Two: Design I looked at images online to come up with a design for my windows. Once I decided what I wanted the windows to look like, I cut a sheet of paper the size of my window and drew my design on it. Tip: I used a sheet of gift wrap paper because it is large and has one-inch grid markings on the back, which made it really easy to draw measured lines.
Step Three: Clean and Outline Make sure your window is clean and dry. I outlined the window with the leading strips, measuring and cutting them with a razor blade at the points where the perpendicular strips would meet. The strips are adhesive, but I found that they didn't stick extremely well. I had read about this on the reviews for the product. Because of this and the fact that my practice art peeled off the glass easily, I was concerned that the finished design wouldn't last long. By the time I had finished the project, though, I was more assured.
Step Five: Crystal Clear Window Color The next day, I squeezed some of the crystal clear window color into a small disposable container, and using appropriate width paint brushes, I carefully painted in the areas I had chosen and let it dry overnight. Note: I had practiced my stroke technique on my practice glass beforehand. One of my concerns was how difficult it might be to remove the paint from my window later if I didn't like it. I found that I could peel the dried paint off the glass in a whole piece. Again, I wondered how lasting this artwork would be.
Step Six: Liquid Leading The following day I squeezed a dot of the liquid leading on each joint where the strips met. I let this dry overnight. I thought the liquid leading would dry like paint, but actually, it dried like rubber and really held everything together in place. The next day, I cleaned up any straggles by slicing it with a razor blade. It was stretchy and didn't slice easily, so try to be careful to not be too messy with the liquid leading. I had practiced this ahead of time too, and while it holds the art together, it was not too difficult to remove from the glass.
I was really pleased with the final results, and I feel more confident that this artwork will last a while. If not, I don't think it will be hard to remove or that it will ruin my window surface. (Update: It has now been two years since I decorated my windows, and they look as good and are as stable as when I first finished them.)
I used Crystal Clear window paint, but it comes in many colors if you want to simulate stained glass. Here is a link to the product page where you will find more detailed information:
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