Why are there cardboard-sided, plastic-sided, metal-sided bobbins?
It doesn’t matter whether the bobbin is made of metal, plastic, or paper as long as there is sufficient strength to hold the thread. Plastic has improved over the years and is much less expensive than metal so most machine manufactures now offer plastic bobbins with their machines. Although most brands make their own plastic bobbins, 70% of machines now use the generic L size bobbin and it is not necessary to buy brand-specific bobbins. If your machine uses the L size bobbin, you can use either your machine brand bobbin or generic plastic or cardboard-sided bobbins. Pay more attention to the quality of thread on the bobbin than whether the bobbin is cardboard-sided or plastic or metal. Both the metal and plastic bobbins are reusable. L-size cardboard-sided bobbins are the original standard. L-size plastic-sided bobbins have the same diameter and core size, but some are slightly taller. The advantage here is that it holds more thread. If the bobbin case is designed to hold a taller plas
