ALWAYS use polyester and NOT nylon. Superior threads is superior, as is YLI thread. Lakeside Quilting (Donita Reeves) carries a very thin (and I do mean thin) thread which she uses instead of invisible thread and it comes in colors and works fabulously. Sorry can't remember the name but I'm sure it's on her web site. I'm not home so can't check the name. One small spool goes a looking wY. Can get a sampler box of 5 different colors ver reasonably priced. Hope this helps.