Closed-cell (non-porous / non-absorbent): Mats comprised of a closed-cell surface do not absorb moisture such as sweat and bacteria. This allows the mat to be kept very hygienic and last much longer over time with use compared to mats that do absorb moisture. The downside of this material, if you are warm/sweaty at all, the mat will feel slippery, so we always recommend pairing it with one of our hand towels to absorb moisture and provide extra traction. If you're practicing hot yoga, we recommend a mat towel for full mat coverage.Open-cell (porous / absorbent): Mats comprised of an open-cell surface absorb moisture. This allows our open-cell mats to offer its exceptional grip. The downside to this feature is that it will not last as long, in general closed-cell mats are more durable over time.Here is the breakdown of each of our Manduka mat Series and which are closed vs open-cell:PRO Series – PRO, PROlite, PRO Travel – These mats are made using a closed-cell material, meaning nothing can be absorbed into the mat, and the mat can be cleaned thoroughly on the surface every time.eKO Series – eKO, eKO Lite, eKO Superlite – These mats are made of a natural rubber, also a closed-cell material. These mats can easily be cleaned and disinfected but need to be dried properly, particularly if the top and bottom mat surfaces are cleaned.GRP Series – GRP, GRP Lite, GRP Adapt – These mats are made from an open-cell PU top layer and rubber base construction. The goal of the PU upper layer is to absorb moisture and provide maximum grip as it gets wet, so thoroughly cleaning these mats requires the most attention and care because this material is very absorbent. Foundation Series – Manduka X, Begin Mats – These mats are made using a TPE closed-cell material, meaning nothing can be absorbed into the mat, and the mat can be cleaned thoroughly on the surface every time.