The original post that inspired me: http://www.craftster.org/forum/index.php?topic=327588.0#axzz2pOF0kWso
I've been wanting to make my little girl a unicorn shirt using this method ever since I first saw the original post.
Here is a attack of how I did it.
Sharpie pens in any colors you'd like
a t shirt or fabric
sponge brush or watercolor brushes... I used some of my kids' brushes.
a frame of sorts to stretch your fabric so that it doesn't lay flat against any surface.
First I stretched the shirt over a plastic tote lid, so that the shirt itself was raised a bit & not resting flat against the plastic. I figured this would help keep the colors from running where I didn't want them to run. I think if you're doing a small area, an embroidery hoop or q-snap type of frame would work well too.
Next, draw your design on your fabric lightly. The colors are all going to go crazy & bleed into one another, so you don't have to be precise.
Note: This is what the ink looks like before and after you brush on a little rubbing alcohol.
Then loosely color it in leaving white spaces in between your lines to avoid it getting too muddy looking.
Next, you brush on the rubbing alcohol all over the areas you want the color to explode & run together. Note that it's sometimes going to go where you don't expect it to... as Bob Ross would say, these are happy accidents. Especially on a kiddo's unicorn shirt!
You can add more color & rubbing alcohol as needed to get your desired effect. I did more linework & shading here...
Finally, you'll want to heat set your sharpie ink before you wash your shirt. I let it dry completely & ironed it.
My little girl loved it! I hope you find yourself inspired to try this method & come up with your own fun designs!