I do recommend swatching before you begin a pair of Thompson River Socks. These socks are made with a worsted weight yarn. The gauge and number of stitches will be different from what you might have used to make a typical pair of fingering weight socks.
The good news is that a swatch for these socks, even one made in the round, will not take very much time at all. A few weeks ago, in my post on my October Baable Hat Class, I wrote about making a colorwork swatch that simulates working in the round. For the Thompson River Socks, you may easily go one step farther, and actually knit a swatch in the round -- and you will even be able to try it on for size!
There are three sizes in the sock pattern. Each size has its own Cable chart. The three sizes have finished circumferences of 6 (7¼, 8¾)". The charts have 18 (22, 26) stitches.
How to swatch for Thompson River Socks:
1) Measure the foot circumference at the widest point. Typically socks have some negative ease. Usually a sock knit with a circumference of about 1" less than what the foot actually measures is ideal. (There is a good amount of tolerance on this.) The foot in the photo measures about 8½". The swatch measures 7¼". The same foot looked comfortable and cozy wearing one of the 7¼" sized magazine sample socks.
2) Find the chart for the size you will be making. Double the number of stitches in the chart for the amount to cast on for your sock swatch. For the three sizes that will be 36 (44, 52) stitches. Cast on with the needles you will use to knit the socks. (These will be your favorite kind of needles to make a small round: two circular, double-pointed or magic loop.) Place marker and join to work in the round. Knit 1 round.
3) Next round: Work Cable chart over 18 (22, 26) stitches, place marker, knit to end of round. Continue in pattern for about 2½" Bind off all stitches.
4) Block, if desired, and try swatch on foot. The stockinette portion represents the sole of the sock, and the cable pattern portion the instep.
(You can apply this method to swatch for other socks, as well.)
When I was working on this design for Interweave Knits, Fall 2016, I made many similar swatches.
I do enjoy swatching. Why don't you give sock-swatching a try! ♥♥♥
Thompson River Socks will be the class project for a two-session Saturday afternoon class at Gosh Yarn It! in Kingston Pennsylvania, November 12 and 19, 1:00-3:00PM.