Strange marks on blinds
Hi. We winter in Phoenix and ever year when we come down, I have these strange marks on our kitchen blinds. The place is locked up during the summer and the AC is turned off. I've tried vinegar, bleach and TSP, but nothing seems to remove them. I don't know what is causing them strange orangey brown marks, but the don't want to come off. Anyone have any idea what would cause this and how to get rid of them?