CircleofCrafters.com and Iris-Folding.com have a variety of different iris folding patterns that are free to print and use. To view the patterns at Iris-Folding.com, click on Free Templates on the left-hand side.
Scroll down the page on CircleofCrafter.com and under Free Basic Iris Folding Templates, click one of the shapes. Free patterns are available for a hexagon, square, pentagon, oval and triangle.
The CircleofCrafters.com page has free and paid templates for iris folding patterns. The site posts one free pattern every month, often going with the theme of the month. For example, one spring had an Easter egg pattern. Some other free patterns include a fish, shoe, hot air balloon, whale, kitten and squirrel.