I tested about 8 Crayola Ultra Washable markers this morning on several colors of fabric. I marked them heavily in the top row, and with a finer point below. Then I let them dry, ironed them, washed them in All Free in warm water, then dried on permanent press. Results are as follows:
[ATTACH=CONFIG]526979[/ATTACH] [ATTACH=CONFIG]526980[/ATTACH] Looks pretty bad!
[ATTACH=CONFIG]526981[/ATTACH]Most of the color washed away. The worst culprits were the reds.
[ATTACH=CONFIG]526982[/ATTACH] It's faint, but clear. Of course, these were big, thick marks. All the fine point marks washed away.
The white fabric was Kona, the others??? I'm glad to have done this as I need to mark a quilt for quilting tonight!