These require a cleated (spiked) backing to "grip" the carpet and prevent shifting.
Thinner mats (economy or regular) are usually sufficient. CHAIR MATS
The backing of the mat is the most critical feature to match to your flooring. These require a cleated (spiked) backing to "grip"
Requires extra thick mats with longer spikes to prevent "dimpling," which is when the chair sinks into the mat, making it impossible to roll. 2. Comparison of Materials Chair Mat Buyer's Guide - MyBinding.com CHAIR MATS