I use Pigma pens. I used to use a really thin tip but have decided that a #8 tip works the best and comes out the darkest. You have to heat set it with a dry iron. By using the large tip, I feel as though it will last longer and stay longer with washings. Good Luck!

Thanks everyone. I found the Pigma pens at ACMoore, neither Michaels nor JoAnn's had them. What started as a gift from 10 friends ended up being the "sign-in board" for about 50 other people at an 85th birthday party. It's a good thing that I bought 2 new pens!!!!