okay guys....I'm opening this thread up again. I have two Olfa rotating cutting mats...they are at least 20 years old and the green color is getting paler in the middle (where I guess I cut a lot). I like to utilize the heck out of my stuff.......but, I'm not sure this is a good thing for the mats. How do you tell when it's time to replace them? I did pull out my brand-new 17" rotating cutting mat and used it last night. It seemed to cut much better with the same rotaty cutter. So, I'm assuming the other 2 are old. I've seen where people rejuvenate them by soaking them in a tub, etc. Have any of you successfully done that? Does it enable you to use them longer or is it worth it? Lastly, if it's time for them to be repurposed........what do you do with them? They are the rotating ones, so can't flip to the other side. I guess I can use them to protect the surface of some of my sewing room furniture (but I've already gone some old mats there). How long do you keep yours? Did mine have a good run? Let me know your thoughts. I just don't want them going to the landfill without squeezing out their last bit of usefulness! Thanks!