Swatching for swimwear is a little different than swatching for regular crocheted items. Here is how I do it:
1. I make a swatch
2. I trace it's size on graph paper in PENCIL (instead of measuring, it doesn't have to be perfect)
2. I weigh it on a cheap kitchen scale.
3. I make a note of it's "dry weight" on the graph paper.
4. I wash the swatch in cold water, delicate and leave it damp (don't dry it).
5. I weigh it wet and note it on the graph paper.
6. I trace it's size over the top of it's first tracing, this time I use pen or a different color pencil and note how much it shrunk or grew while wet.
7. I note if it seemed to lose any color.
8. I take an intuitive measure of "how heavy" it feels in my hand compared to it's size. (You know how fine China should feel light compared to how big it is...same goes)
9. Then I lay it flat on a towel to air dry.
10. After an hour, I go check to see how much it dried in an hour (imagine sitting on a beach, I'm wondering how long it would take to dry off. Too bad I can't factor in the sun!)
Then I make a decision, "Is this something I'd be willing to wear in public, in the water, or is this something that I would only sunbathe in?"
Hmm, anyone out there actually worn a crochet swim suit in the water? Tell me what happened!