Here's a suggestion for your old mats: Taken from Muskogee Area Quilter's Guild newsletter for March, 2010.
Recently, while at a show, I had the opportunity to speak with a representative of the Olfa company. One of the questions he asked me - after determining that yes, I did have an Olfa cutting mat and rotary cutter (amongst others), how often did I perform maintenance on the cutting mat? Cutting mat maintenance? What was that? Was I a bad mat owner? Obviously, I had managed to achieve that "deer in the headlights" look, as he chuckled and told me that most people do not realize there is maintenance for the mat and through good maintenance the mats will last many years longer. Okay, I admit, he had my attention now, we all know how expensive cutting mats are especially if you have a larger one, rotating / revolving, etc. He told me the maintenance is simple: #1. after cutting a project (or at least once a month), wipe off any fuzzies or debris from the mat #2) then wipe down the mat with a mild soap and water solution - dish soap in warm water is perfect and a sponge with a scrubbie side dipped into the soapy water and wrung out well will really do the job #3. wipe dry. All right simple enough. Then he went on to explain that just like our hands, fabric has a habit of pulling moisture out of the mats, resulting in them failing sooner - deeper cut marks will appear and they can actually become very hard which can result in damage to the rotary cutting blades. Now I could see my savings doubled - mats and blades. I did scrub down my mats as he suggested and was surprised as to the amount of moisture they absorbed and the amount of dirt that was removed - I thought they were clean. My cutting mats that were getting that tired and worn look are now fresh and ready for the next project.