Well I haven't even worn my Ben Folds shirt yet and already I ruined it.
After painting a shirt it needs to wait 72 hours before it can be washed. Before washing it the first time it need to be heat set so that the paint adheres really well. This is done by just ironing the shirt with a pillow case or something thin over top of the paint.
However I used a different type of paint on my Ben Folds shirt. Michaels ran out of black matte paint so I bought a velveteen paint thinking that it would do just fine. It seems that the velveteen paint just can't be heat set, as you can see below. It bubbled up and went all puffy and gross, so I'm going to have to redo the whole the shirt :(