I have an old Designer 1 (VIking) and use pre-wounds a lot. I can't wind the empties on my Viking bobbin winder but can wind them on my quilting bobbin winder (separate machine). I found I can't wind them fast on that machine as they tend to snap in half so wind them about 3/4 full and use them till they break on me. My Viking takes the special Viking green bobbins and I have no Viking store nearby so reason for using the empty Neb pre-wound bobbins. I can use these Neb bobbins in my Brother, Babylock and Viking too.