my daughter has a huge gymnastic meet coming up and Carly Patterson will be there signing autographs and my daughter wanted to have a t-shirt signed and usually at these events they are signing with a sharpie...I figured I should ask as it would be my luck to get the whole shirt prepared and then have it wash out on the first wash...
Sharpie does fade over time which is why the fabric markers are a better choice for tees. It does take many washings but eventually it will start to fade. My daughters have some tees with sharpie signatures from school and Girl Scout events.