I found another handspun singles for the second pattern weft on the lampas tree project. It's a variegated yarn in a relatively dark tonality, and will thus be a good foil for the gray yarn. Here are the three shuttles lined up, ready to weave: the black is the cotton ground weft, the middle one is the variegated singles pattern weft, and last is the gray pattern weft.
I think I have enough of both handspuns to comfortably complete a 6" high book cover.