i use cone thread, signature, maxifil, quilting, i just buy the biggest cones i can find and then use them on serger, sewing machine, and quilting machine...the cost is one factor, the color availability is another... and the flexibility... I buy 3 shades of gray, black, and white in 4 cone lots for the serger, BUT everything else is in 2 color lots, just for the needles on the serger.... if i am sewing something that matters, the colors go on the 2 needle places, and the appropriate gray goes on the last 2 places... colors for the sewing machine, colors for the quilting machine, grays are for general sewing and quilting on the serger... ps........when i buy whites, i DO buy 2 whites, palest cream and palest ecru....that way when using 4 whites, one of them will be just right for the 'seam needle' that shows... i just move it to the right place and all the other whites are moved to accommodate it...