Fluff mostly happens when using cheap(er) cotton thread - e.g. serger thread - which is made from short fibers - hence the fluff. Quality cotton is made from long fibers, like Egyption cotton. Madeira has prime quality cotton - called Cotona - in several weights. I used to use it for (handmade) bobbin lace -like the Battenberg and still have some left. It's a pleasure to use it for embroidery.

thank you for this info-I started with Zwicky 100% Mercerised cotton but it is nothing like the old Coast Sheen - I have bought some Mettler from Bernina but haven't tried it yet. We don't always get all threads in SA but I will be on the lookout for Madiera