Checking my first swatch, if you remember, it was 21-0-21 sts. The reason for that was I could measure it with the green gauge to see what sort of stitch count would result from the stockinette. Hopefully you can see, even on the T9 part, it was 32 sts to 10 cm. The design I want to use is that ‘swing-style tunic’ that is quite wide at the hemline, like finished circumference of 150 cm/59 in. and the 32 st count would at best get about 128 cm/50 in. To get a wider fabric that still has the look (flat front, nothing too exotic) and simplicity of stockinette (single bed knitting), I like to use that one-row-tuck (1RT) https://knitwords.blogspot.com/2023/05/egg-on-my-face.html
that I’ve used many times before. If you need more reading, put 1RT in the search box at the top left of this blog page and it will bring up a ton of stuff that I’ve posted in the past and by the way, using the standard gauge electronic machine here but can be done on a punchcard machine - see above link!;)
Made real swatch - going with that HodgePodge trim, https://knitwords.blogspot.com/2020/07/half-cocked.html
With my favourite 1RT, at T8 and T9. Measured the swatches, hot off the machine, then wash and dry, measure final - this way you can get a feel for the amount of shrinkage, maybe for future reference, but also note, the majority of shrinkage is in the length. T8, 27 sts and 46 rows, became 28 sts and 52 rows. T9, 25 sts and 42 rows, ended at 26 sts and 46 rows.