A tightly woven outer layer, brushed microfleece interior and a DWR coating allow a soft shell to repel most weather while remaining highly breathable to help you manage temperature and moisture levels efficiently while performing aerobic activities.
Sitka outer layers are originally treated with a Durable Water Repellant finish (DWR), which keeps the outer fabric from becoming saturated so that the breathable barrier can do its job. This coating needs to be replenished once per season, or more often if the piece gets a lot of use or washing. If water is no longer beading up on your shell, it's time to repeat it.
In general, washing your gear in cold or warm water with mild non-deoderant powder laundry soap (non-toxic, biodegradable types preferred) and hand drying it are the best ways to clean Sitka products.
Freeze it and then pick it off with a dull object. Rub the remainder out with a water and white vinegar solution and then wash with detergent.
Like most synthetics, Sika Gear will melt or burn when exposed to flames or direct heat. Use caution when around fires, stoves and hot metal surfaces!