Some automatic stripe generators, which may come in handy for your custom fabric designs for Spoonflower:
Both online tools allow multiple colors, orientations, and stripe widths and allow free downloads of your results. You can also submit your designs to a user gallery. However, both are far clunkier and confusing to use than their “web 2.0″ labels would lead you to believe … sigh.
Random Stripe Generator: I wrote this script to generate random stripe patterns for knitting sweaters, scarves, blankets, etc. It’ll give you an idea of what the finished sweater will look like, but it still leaves some unpredictability to the stripe pattern. Limited color selection, but I like the randomness feature.