The plastic is a little too soft as my roller chair sinks into the divots made by the legs and it is hard to roll out of them. I expected it to be harder plastic to prevent that.
I like this size shape and quality of this mat. My only negative is that despite it having little plastic spikes on its underside it shifts position to easily and I keep having to adjust it.
I have used three of these chair mats two of which were replacements for the first one I purchased and complained about. Each one of them immediately developed indentations in them from the weight of any object placed on them such as a rolling computer chair in my case. This happens even when the chair is unoccupied. The imprints are not temporary and although they dissipate once the weight is completely removed they never fully resolve. In a short space of time so many impressions accumulate that a rolling chair can no longer roll over the surface of the chairmat with ease which was the purpose I purchased this chairmat to begin with. I strongly recommend against purchasing this chairmat.
The wheels of my char sre sinking into the mat and it is hard to move it out of the sunk area. My carpet thickness using the paper clip method is 1/4". I am very unhappy with this purchase.
I wish I could have gotten a matt custom made for thesize of the area I needed it for. I might have preferred one with a lip on the edge to keep my chair from rolling off when I move around. It's taking some getting use to but I think it will serve the purpose of protecting the carpet.