Climbing skins are one of the main elements in a tourer setup. No skins, no ski touring. Touring skins come right under your touring skis and provide grip for you to climb up a slope without sliding backwards.
A skin is made of one sticky surface that comes onto the ski base, the other side in contact with the snow is made of fibre and the skin features a clipping system so you can attach it to the ski.
How does the skin stick to the ski?
The most reliable and most popular way until very recently was glue. Glue ensured a strong grip onto the ski base but it had a few weaknesses (maintenance, storage, etc.).
Up until now, glued skins were your only option but manufacturers have developped new technologies allowing the skins to stick to the ski without glue. We call them 'glueless skins'.