What a great idea!! Do you know how many things we could do with this idea?? colored paint on white shirts, or use bleach in a spray bottle on colored shirts. I may need a 2nd job to pay for my crafting habit :D
DIY shirt cut-out. I usually don't care for cut-outs but this is not so bad. No tutorial in the link but this should be easy to cut out. Just skis and cut out the diamond on paper and then draw it up on your shirt and cut!