Just wondering what types of material people are using on their ramps? Right now I just have a piece of fleece that I pin down at the top and the bottom of the ramp but Harley always gets under it, slides down on the coroplast and then falls asleep under the fleece at the bottom. I think he can't figure out how to get out sometimes... if he'd walk to the side instead of trying to climb back up he'd get out but... he isn't the brightest sometimes. I saw ramps for guinea pigs on ebay made out of coroplast and something else for the flooring... anyone know the one's I'm talking about and/or know what that material is? Oh and any photos of ramps would be appreciated.