PVC, PEC or ?? I am looking for some help in determining the appropriate type of plastic for my application. I am in the process of having a slide chart manufactured out of plastic. It was recommended that I use 0.024 inch thick clear PVC. The samples produced with the PVC were fine with the exception that when I left one in a briefcase in my car on a hot summer day, the slide chart took a permanent waviness to it. I’m guessing the car got hot enough that PVC hit a temperature transition point. The manufacturer is now recommending PEC for the application, which is suppose to be more susceptible to higher temperatures. Can anyone verify that PEC would be the way to go or recommend a different material? My goal is make a durable slide chart that last through normal wear and tear. Surviving the temperatures of a hot car might be excessive, but I would like to make the best product I can.