I had a proper look at the white yarn yesterday and sorted it all, even the stuff with no labels. Turns out I have not only 4 ply (fingering) and doubleknitting, but 2 ply and 3 ply as well My Auntie knitted a christening gown and shawl for DS in very fine yarn, so I expect those are left over from that.

I have enough dk to make a lap throw, and could use the fingering weight doubled as you suggested Anhata, to make covers for throw pillows, maybe. I love the garter and loops pattern.