Some times it is just a question of what you can afford to use. I have used everything for everything....the only one I really stay away from is Hand Quilting thread, not recommended for sewing machine use.....I have A LOT OF older thread, and am trying to use it up, "Waste not...want not"....but if I was to buy new, now that is a different question. I would only buy Superior Thread "King Tut" for machine quilting.....love the look, love the fact that it is very low lint, but it is $9 a spool....so I buy on sale when I can. I have quilted with serger thread and embroidery thread, I have used polyester thread on cotton fabric and cotton thread on polyester fabric..... sometimes the color is more important.