Hi, I've recently started to convert my negatives to digital. I have a folder of old negs from containing college projects from when I studied photography in the early 90's. The negs are stored in paper/plastic wallets and a few of them have stuck to the paper on the reverse side of the negative. Some of the negatives have marks where they were stuck to the paper - it looks like the paper has stuck to the negative. I'm just wondering if these can be easily cleaned and if so, whats the best way to clean them? Also, is there a better way to store negatives or should I just make sure that I swap out the wallets for new ones every so often?