A classmate was showing me how he uses the Adobe Shape app for iPhones and iPads as a sketching tool when he is planning his compositions, and I realized that the App has potential for converting some of my photos into line drawings that are suited for reproducing on shirts, etc. For a while, I have been wanting to use one of my photos (from the work I do with animal rescue groups) as a design for a fundraising tshirt, but I found that photo printing on shirts has limitations when you do small-run printing.
The Shape Application, however, creates some really interesting designs that have potential for this kind of thing. It only works with certain high contrast photos, and you'll probably try it on 100 images to find one or two that work, but I did luck out and I have a few images that look promising.
I ordered a single shirt from CustomInk to try it out and it looks promising, although I want to try a different tshirt design before I order a larger volume of shirts.