I swatched 5 yarns and used a US size 9 needle for all 5 swatches. The Loro Vest calls for 16 stitches and 26 rows over 4 inches in Moss Stitch on US size 9 (5.5 mm) needles.*It's important to remember that needle sizes listed on ball bands and in patterns are only a suggestion. The phrase "change needle size if necessary to obtain correct gauge" means that you might need to go up or down a few needle sizes to achieve the right number of stitches per inch for your chosen pattern.
I should also point out that for this particular pattern, row gauge in not terribly important. The pattern instructs you to work to specific lengths and since there are no sleeves to worry about, it's not absolutely vital that you match the pattern's row gauge, which is 26 rows over 4".
Because the pattern gauge is taken from a non-curling stitch, I decided to forgo the usual garter edge stitches and just cast on 16 sts, knitting until the cast-on edge could be folded towards the live stitches on the needle, making an isosceles triangle. I bound off in pattern and measured the swatches. After a quick dunk into warm, Soak-laced water, I let the swatches dry and remeasured them, noting any major changes to the feel or gauge.
- Quince & Co. Osprey Heathers: pre-blocking: 3.75” (4.25 sts/inch); post-blocking: 4” (4 sts/inch). The stitches are nice and even and the fabric is soft and cushy. The stitch definition is good and there were pleasant tweedy flecks in the heathered colorway.
- Cascade Ecological Wool: pre-blocking: 3.75” (4.25 sts/inch); post-blocking: 4” (4 sts/inch). This is spot on for gauge and feels perfectly wooly. This is an economical choice for me since I already have the required amount stashed. It's also lightweight, which means it isn't lightly to stretch out of shape.
- Madeline Tosh Vintage: pre-blocking: 3.25” (5 sts/inch); post-blocking: 3.75” (4.25 sts/inch). This is a dramatic change, and I'm not surprised! Superwash merinos have a tendency to splay wildly when they hit the water. If I wanted to tighten this up and get back to the original gauge, I could toss this in the dryer on low heat. But, the gauge is far from what I need, entirely too light.
- Peace Fleece Worsted: pre-blocking: 4.5” (3.5 sts/inch); post-blocking: 4.75” (3.25 sts/inch). This yarn blooms beautifully and the mohair content provides a soft halo that obscures the stitches somewhat.
- Zealana Tui: pre-blocking: 5” (3 sts/inch), post-blocking: 5" (3 sts/inch). The possum content bloomed, making the surface look and feel soft and cozy with a taupe brown halo. The stitch pattern is somewhat blurred, but the overall effect is quite nice, and feels luxurious.
While there are two yarns that match my desired stitch gauge exactly, and I could change my needle size to coerce other yarns toward my goal, I'm temped to use Tui, which is a bit too chunky. You can sometimes get away with this by knitting a smaller size, or vice versa, knitting a larger size with too-light yarn. I only recommend this when a garment has very simple construction. Loro fits this description!
To see if I could pull this off, I flip to the schematic. I see that the size I was going to knit, a Medium, should measure 21.5" across at the Back lower hem. If I use the Tui at 3 sts to the inch and follow the pattern as written, my Back lower hem would measure about 29" across--close to 8" more than what I need. If I follow the directions for size Small, the piece will measure approximately 25" across. That's still almost 4" wider than what I need. I have some thinking to do! Either I can tinker with the pattern or use a yarn that is closer to the gauge of the yarn used for the original, Madeline Tosh Merino.