I just spent today in a B&W printing day workshop. Came out with a nice print I'm happy with. But, I forgot a towel..and didn't have apparantly dry enough hands, and I think, I got fixer? on my 11x14 final prints...all three of them but barely noticible on the third. It's a yellowish/brownish stain. I tried rubbing it out gently when in the final wash to no avail.

Any ideas how to get rid of the stain?