I use the small soft plastic wheels made to store bobbins, this product's most appealing feature is the ability to hold the bobbins in place even when I drop it. I label each wheel with the thread weight or name. This allows me to match thread from my large rack with the bobbins with accuracy, and to pack them with ease when I travel to retreats and classes.
Great idea. I sometimes look at the bobbins in my wheel and don't remember if it is embroidery or regular thread