DARN TOUGH MENS SOLID LIGHTWEIGHT CREW SOCKS RYE - MENSMerino Wool yarn is indeed a fine yarn thin, silky, nothing like rag wool. For our more casual socks and dress socks, we knit using our thinnest Merino with a watchful eye over a performance fit. This means our lifestyle socks are sublimely smooth and wrap your foot, truly seamlessly, without bunching or slipping. Add wools ability to stay dry, resist odor, and regulate temperature, and you have all day comfort. At least.