Trying to find info here that compares different types of clothing materials and the amount of warmth they retain (or lose) when wet. Can't find anything via the search tool but I know there's probably a lot of discussion on it. Can someone point me to a link somewhere please? Thanks

You probably won't find much on SP on specific material testing protocols ('soft goods' or 'hardware'), but you might want to contact some of the manufacturers with your questions. I know The North Face used to have a pretty extensive lab when they were based in San Leandro, California; that was in the 1980s-1990s before they got bought out and had numerous mgmt shake-ups. They do have some info on their website, but due to the competitive nature of the outdoor products market they probably won't give you any specific info on new products/new materials they plan to use in future products:

https://www.thenorthface.com/about-us/t ... n/rdd.html

Black Diamond (and their predecessor Chounard Equipment) also used to have a pretty extensive testing lab for climbing gear (carabiners, nuts, cams, etc). Similar to The North Face, they probably will be somewhat evasive about revealing too much to you if you inquire about their specific materials testing standards, new materials they are researching right now, or new products:

http://blackdiamondequipment.com/en/about-us.html

Feathered Friends also has a little bit of info on their site:

http://featheredfriends.com/fabrics/

A lot is going to depend on the specific fabric (weave type and/or pile length => thickness and permeability), not just the fiber. Off the top of my head, for similar weaves,

cotton: wets quickly, absorbs a lot, stays wet

typical synthetic base layer: absorbs less, dries quickly. ( Under Armour made its name by selling undershirts to football teams. The synthetic shirts saved the teams a fortune in laundry costs by drying faster.)

wool: wets slowly, can absorb a lot, dries slowly, still retains some effectiveness when wet

down: wets slowly, clumps up and becomes ineffective once soaked, dries very slowly

Synthetic down: doesn't wet easily, still fluffy when soaked, retains some effectiveness when soaked.

Google for "Dynamic Rewarming Drill" if you haven't before...