Record Sleves

@billstevenson I always read your comments and consider your knowledge and experience in these matters.  Thank you for sharing.  

@billstevenson Interesting observation. Mildew is tied to high humidity. I've been storing my records in outer sleeves at room temperature in Switzerland and California since the mid 80s. Not one case of mildew. Air conditioning in Florida may have contributed to the problem, as Florida in general has humid air, For archival storage one would also need to address the humidity issue, not just temperature. Removing water from the air is more complicated than adjusting temperature only. I very much doubt that the outer sleeves contributed significantly to mildew formation. The main culprit is humidity. I work on the board of a non-profit, which has a mold infested book collection in Florida. No sleeves, but high humidity, lots of mold.

@oberoniaomnia You are certainly correct that mildew comes from high humidity. Outer sleeves would be a barrier to air circulation and evaporation.  As you say this is a complex problem.  I am glad you have not had to deal with it.  I had not dealt with it either until the encounter mentioned in my previous post.  Each collector must assess for his or her self what actions to take to preserve their collection.  Sharing knowledge is always helpful in my opinion.  Use it or not, that is your prerogative.