Thank you so much for all your good advice yesterday on my Cherry Tree Hill DK question! I took it to heart; here are the results.
First, following Carrie's advice, I checked Ravelry for comments on CTH Supersock DK. No luck.
I did, however, find seven sock projects there using the yarn, so I sent a message to each of those Ravelers asking about their experience with washing their socks. What I learned was that many people are far more careful about how they wash their socks than I will ever be -- they wash them by hand or on the gentle cycle in their machine in cool water and do in fact lay them out flat to dry. Huh.
Never one to be totally won over by other people's opinions or experience, I followed Erika's advice and swatched the CTH for my own laundry experiment. As I did so I remembered several other yarns in my stash that had I purchased with sock intent but about which I had reservations. So I swatched those, too.
Yesterday and today were laundry days, and each of these swatches went through the washer and dryer twice, in the company of blue jeans, dark t-shirts, dark sweatshirts, and other socks. Before I threw them into the washer, though, I traced around each one so I could judge shrinkage. For the record, my washer is a first generation Maytag Neptune front-loader circa 1998 and the dryer is its mate. I washed both loads in warm water with cool rinse on the "sturdy cottons" cycle and dried them on medium temperature, which in this dryer is still pretty darned hot. The swatches were all a bit wrinkled and rumpled when they came out of the dryer so I steam-pressed them but was careful not to change their dimensions.
Cherry Tree Hill Supersock DK, swatched on a US#1, shrinkage = a little:
Felting, none:
One Raveler did mention, though, that her CTH socks did not felt in the first wash: "The socks I've made that have felted have always taken several washings before they begin to shrink noticeably." So perhaps my results are inconclusive. I'll wash the swatch a few more times in the coming weeks and see what happens.
The second yarn I swatched was the Pagewood Farms Denali hand-dyed sock yarn that I bought at Yarnover a couple weeks ago. The lower part of the swatch was knit on a US#1 needle; the upper part, above the row of purl stitches, was knit on a US#0.
The results, shrinkage = minimal, and possibly confined to the lower portion:
Felting = none.
This makes me very, very happy because I love that yarn and look forward to knitting it -- on an Addi US#0 -- into a pair of socks for myself.
The third yarn was Araucania Ronco Multi, swatch knit entirely on US#0.
Shrinkage = oh, yeah, I gotcher shrinkage right here, baby.
Felting? We got that, too.
I am very glad I tested this one -- a pair of socks knit from it would have been unwearable after two washings. Must ponder: knit them too large and be the proud wearer of a pair of felted socks? or use the yarn for something else?
I think I will throw swatches #1 and 2 into the wash a few more times so I can be sure of the results. In the meantime I'll knit other things.
=Tamar gave some excellent advice, too: