Silk is a great base layer material. Here are some attributes of silk:
- silk is the most hypoallergenic of all fabrics
- silk will absorb perspiration while letting your skin breathe
- silk has a smooth surface resists soil and odors well
Although silk is not as warm as merino or yak wool, it is barely noticeable under your clothing. You can wear it everyday during the colder months.
Here is a list of silk base layers: