My Ilford set of filters is very old, I do clean them but they have a few scratches and smudges. Never a problem as they are behind the neg. Charlie, the Ilford MG FB WT is a really good paper. Specially with negs a little long in the toe. My favorite filter is the 2 1/2 processed at 2 1/2 min. (funny how that works out) Anyway they usually start to come up about 45 seconds. I do pre- soak and squegee to swell the paper. I find that negs a bit under (1/3) over processed (14 min) agitation: 3 @ 30 sec then 8 @ 2min 3@ 30 2 @1min seeems to work great for this paper. Good luck with it!!