I have placed my brushes and rollers for that matter in saranwrap, and in the freezer. It did not harm the brushes or paint. You just need to give them enough time to un-thaw prior to using them. I left them in from a day to a week, and they were fine. I was a little worried as well, but I had no problems. The paint I was using was water based, you may want to look into this further if you are using an oil base paint.