Like so many colors, White is a HARD color to match from brand to brand. Guterman white is almost a blinding white, next to so other brands. It's kinda of like paint you have white, egg shell white, white white (or hospital white). I will only use one brand of thread if I'm free motion quilting (or topstitching of some kind), if the stitching isn't going to show I mix it up all the time. You might also see a color difference in whites if you use pre-wound bobbins too, but it's still ok.