Find a photo of a stained glass window and print it out on vellum paper. Practice on regular paper and use 'fast draft' to save on ink while you're tweaking the size. The size should be exactly the same size in diameter as the diameter of the clear glass ball. This one is irridescent, but clear works better if the photo has a lot of detail. When you get the picture size correct, print it out in 'best draft'. Roll it carefully around a pencil, and insert into the ball. Use the pencil to manipulate the photo so it's centered horizontally and vertically. These are really lovely when placed in front of a tree light.