We need an image to understand exactly what do you mean before suggesting anything.

Thought I had already uploaded one, sorry.

I think your films were exposed to light. Open a new box of films and compare.

That doesn't look like light exposure to me. If the film were exposed to light you'd expect to see a more even, matted dark area. It looks as though there's an issue with washing your membrane; most likely that your rinse solution has something growing in it that is a) adding artifact to the membrane and b) has changed the pH of your TBST or PBST such that antibody binding is impaired. Is it at all cloudy?

I'd make new solution and scrub out the bottles containing your wash solution.

If it's affecting all westerns then it must be something common to all of them:

-developer (unlikely as other people would have noticed problems too)

-film exposed to light (may have gone unnoticed if you're the only one in the lab using that box of film but that image doesn't look like light exposure to me)

-dirty wash solutions (my bet)

-a hot of other issues (something strange with the transfer box etc).

Let us know if making up new, clean, well pH'ed TBST/PBST works. If you're reusing antibody that was diluted in the previous batch of TBST/PBST then you might need to make up a fresh batch of that as well.

Yeah, I think you're right about the wash solution. I had been using the same bottle for my TBS-T for a while, but changed it out a few days ago. Everything I've washed and developed since has looked a lot better. Thanks.

Oh Max, today i go through ur blot, dnt worry i also faced the same problem, kindly let me how long u r keeping ur blot with the developing solution, use max 5 mins, then drained out the developing solution properly with the tissue paper , holding at one corner of the blot and bend it so that the liquid will drained out, because if there is patchy liquid and dry region it makes difficult, hope u will get better blot now, best of luck