We've been collecting balls of deadstock specialized darning thread for ages, and swear they made it better back when everyone used it. (Can you even get it at all now? If you can, certainly not easily.) These 75-yard balls of "plain finish" cotton thread are unused, or very slightly used, from venerable brands J&P Coats, Coats & Clarks, Lily and Gilt Edge, and they are wonderful to work: smooth, even, no catching, splitting and knotting. 4 ends of 2 ply means four strands, each strand consisting of two threads twisted together. Colors as listed. Price is per ball.