Tunica : wool type needed?

[M. Demetrius]

Nope. Can't beat the printed selvage. You might consider trying to unravel thread from the warp (often stronger than the weft). Might not be as "thin" as you'd like, but it's certain to be a color match, eh? Most of the time, the yarn in a piece of cloth is not a strong as thread made for sewing, so you'll have to be careful not to break it as you sew, but it works.