Merino long sleeve baselayer a quality feeling baselayer made from 100 merino wool merino wool is a natural material excellent at regulating the bodys temperature and wicking sweat away from the body merino wool is perhaps one of the best materials for a baselayer to be constructed from it is a natural material and can be used for most of the year during the cold winter months where it has excellent thermal properties but is also extremely breathable so great for spring and autumn 100