When purchasing a yoga mat one should considering its material, thickness, texture, color design, and its price.
Yoga mats aka non-slip mats are specially made to be used in studios or any place it can be placed to prevent hands and feet from slipping during practice. The first yoga mat was made of PVC, which is most commonly used. Another material used with yoga mat are rubber. Due to its traction and sticky grip it is used mainly for people that participate in hot yoga or mainly for people who just sweat. The natural mats made of recycled material (organic) are usually more comfortable in seated positions and or low levels of practice.
A headstand is the ideal approach to test out thickness. Many yoga mats do not require a lot of cushioning. Somebody who's into head poses may do best with a ¼ inch thick, while a person who travels with their mat everywhere may need a thinner mat like a 1/16 inch thick. An average measure of thickness on the mat helps keep balance, while in different poses.