@ Teri, the size of the tile depends on the size of the starting image you have and how big a selection you make. If you have a tile that is too small to your liking, maybe you just started with a piece of image that was too small. Since it is a kaleidoscope effect, you can easily enlarge your tile first, and then apply the effect. The design will not need to have a sharp starting image. Or, you can also try to use a larger scale in the Material Properties window when you select your tile. Give this a try.