I really wish I had seen this a few weeks ago. I'm almost done with my clapotis. I did it in a yarn that was in the clearance section at the LYS (50% off!). It is ONLine Linie 88 Feeling in a pale yellow, a yarn I haven't seen, or been able to find, since. It really makes the stitches pop, especially the twisted knits.
Well, here it the clapotis:
and here is what the stitches look like up close.
Also, MissLuLu, if you are using a thinner thread with a smaller gauge, you will need to do more repeats to get it as wide as a normal clapotis. The only difference will be when you are working the straight rows, you will need to do a few more repeats. From reading the pattern it looks like you do the same number of repeats on the straight row that you did on the increase row. For example: If you ended up doing section two (increases) 20 times, you would do section three (straight rows) 20 times also. You would then do section four (decrease rows) 10 times. Everything else (like the beginning and ending) should be the same.
Please, someone correct me if I'm wrong, but that is the way that I am reading it. And I took a really close look. I have a dk weight merino in verigated pinks that I was considering. It's just slightly thinner than a worsted