I swatched 4ply weight smooth silk yarn from colourmart.com. I am going to make a lacy sweater from an old magazine. I used size 1 (2.25 mm) needles and it came out to be perfect 28 stitches to 31 rows for 10 by 10 cm square after blocking. Just what the pattern calls for! I was really pleased to get the gauge from the first attempt. I am very loose knitter, so most people will need bigger size needles to get this gauge. The swatch was washed in hot water with a dish soap, then blocked. After drying it felt quite stiff, but some gentle shaking returned it to being nice and soft.