Thread, thread

[The Wizard of BC]

I'm with Barb on this one. I use Guttermann exclusively. I use the Polyester on my Poly/Cotton Kilts and 100% Cotton on the 100% Cotton kilts. Wool Kilt are sewn with only 100% Polyester.
For basting and hand stitching of straps I use upholstery thread. This is thick, very strong and waxed. Some people don't like the waxing but I find I can re-use the basting thread by simply ironing it straight.