I use mainly Aurfil 50 also....I have a good supply of it....one of the best prices I have seen is at Hancock's of Paducah...they have sales occasionally. I also use Mettler silk finish cotton. I have used Gutterman but actually find it more linty then the others. I have been thinking about using Superior So Fine Poly as I have heard that others like it for piecing…..I do use it on my long-arm and think it might be a good way to use up what remains on the cones when there is not enough for quilting.....