Boots

Two pairs of socks can in fact reduce some friction between sock and foot but essentially the liner sock should be a fine weave and of synthetic material for the best results in keeping the skin drier. A synthetic material will not hold the moisture that a woollen one would. Wool will hold a third of its own weight in water due to its porous nature. Thus with a proper liner sock the moisture will be wicked to the outer sock keeping the foot drier and reducing the risk of blisters. Everyone seems to already understand this in regard to body thermals. Generally you would be told the skin layer needs to be a snug fit to keep the moisture away from the skin. Good luck

Interesting. I used to do this myself (synthetic inner socks, wool outer socks)- but started to find I got hot, painful feet (as in unnaturally, red, burning hot). I was advised by an old-timer I worked with at the time that it was the electrostatic effect between the synthetic and woolen socks. I got rid of the synthetic inners, and the problem went away. Can anyone confirm this explanation, or at least conform that they've found the same thing?

Dont know about that but if I was ever to wear synthetic socks I wouldnt be able to find them in the morning. They would of walked home by themselves humming a merry tune all the way.

There are purpose made liner socks from Bridgedale and Mund and many others. Like thermal clothing they can be polypro or polyester or silk. Polypro is cheaper but loses shape quicker. Synthetic means it is a monofilament fibre and therefore cannot hold the moisture like cotton or wool. Body heat wicks the moisture and it has nowhere else to go other than to the outer sock. Like any fabric though it can be overwhelmed by moisture. A boot that can subsequently move the moisture is beneficial. Of course if the boot is saturated then it all means nothing. Madpom, i would suggest your experience with the liners was due to some other issue. I have used and sold liners for many years and although we aren't all the same and some people will have issues with some fabrics on their skin (notably wool being itchy or scratchy for some), it can be worth ther research.

The point I forgot to mention is that I can run all day in the synthetic socks with runners on with no issues. Just the combination of the synthetic socks with either the wool socks or the leather boots that gave the problem. Anyway - no worries I toughened up and got used to course wool against my feet and soon got over it ...

Other factors can come into play. Anti-bacterial treatments, washing powders. These will react differently on some individuals.