I was going to use any old gel medium I could find at my local craft store to create my shirt but then discovered that Mod Podge has a special medium specifically for photo transfers. I picked it up on Friday and was off to the races.
I decided to experiment on a shirt Connor had and used an image I found online of Slender-Man (he is obsessed with this lately).
I printed out the image, covered the picture side with the gel and placed it on the shirt. It recommends to leave it for 24 hours but I don't have the patience for that kind of waiting when I am excited about a project. So, after about 8 hours it felt dry enough to me to see what I created.
What you do after the "24 hours" is wet the image and gently rub off the paper portion. I wasn't sure what to expect, I thought just the ink would be left on the shirt and I was afraid that it was going to run and smudge onto the white shirt. But no, the people at Mod Podge do not disappoint! The gel medium changes the image in such a way that no smudging occurs and the image itself is turned into a rubbery applique that is flexible and is adhered to the shirt. Disclaimer, the bottle says to only use a dry toner image but I used my inkjet with no problems at all.
The only black smudges on the shirt were from my fingers, it was all those black pieces of paper you see above. I rinsed the shirt out and hung it out to dry - no more black fingerprints.
I didn't cut out the images and over-applied the gel onto the white part of the paper. In this case it worked out nicely as the image looks like an old photo and the frayed white edges just fit.
Onto experiment number 2. I used one of my older white shirts to try and perfect my technique. I printed out this seahorse illustration and cut out all the tiny details. If you like the look of vintage science illustrations, do a Google Images search for Ernst Haeckel (you're welcome).
Connor is more excited about his shirt than he appears in this photograph. He is just practicing his "I am a pre-teen and nothing excites me look."