Cotton works for those initial mirror calm trips. Cotton and wool work around camp but are not great for on the water. The last decade has seen incredible advancements in new fibers and fabrics. We can finally confidentially profess to have products that perform better than traditional materials. Fleece is often synonymous with polyester but in fact refers to the treatment of the fabric.
Fleece begins with loops formed on either side of a base scrim.
These loops are then pulled and shaved. The degree that a fleece is pulled and shorn makes the difference between a good and a bad fleece. Often the outer side will be premium grade while the inside, being inferior and prone to pilling, is usually covered with a liner or other fleece. You usually pay more for the premium grade on both sides. Over time you can see pilling occur due to wear in the drier or hard use.