I made a quilt for the building principal where each staff member drew a block. I used Sharpie FABRIC markers that I bought at Hobby Lobby. Someone used red permanent sharpie, and it bled when i washed the quilt.
when you write on the quilt, iron freezer paper to the back of the block and it will make it easy to write on - just like paper.
Your final choice is going to be determined by how fine or bold you want the writing.
Here's a picture of some of the blocks the staff did.
[ATTACH=CONFIG]541851[/ATTACH]
The whole quilt in case any one is interested..
[ATTACH=CONFIG]541852[/ATTACH]