In response to all of the questions about my friends 'Karl Who?' t-shirt I made her/my CC T-shirt.

I simply bought a couple of cheap white t-shirts (just in case I fucked one up), and bought some black fabric paint and a medium sized paint brush- with a slanted brush, from HobbyCraft, and just wrote the text on the shirt lightly in pencil (free hand) then just painted over it.
Before painting, i put a few sheets of paper in between the front and back of the t-shirt, to avoid the paint absorbing through.
To seal the painted text, simply iron over it.
The pencil can be wiped off with a wet wipe.

Taa-Dahhh!