Bobbins
The sewing bobbin is a crucial part of the sewing machine, as it holds the thread. It is made out of metal, wood, or plastic, and typically has a mini cylinder attached to two wheels at either end. The thread wraps around this cylinder. The sewing bobbin specifically holds the bottom part of the thread on your sewing machine. Many sewers keep spares of their bobbins on hand which prevents waste when it's time to change colors. When you're buying new bobbins, always consult your sewing machine manual for compatibility. Carefully read the manual for your sewing machine before selecting a bobbin in order to avoid issues. Depending on the model, you will either need a metal or plastic bobbin. After you purchase a sewing machine, you will probably need to buy bobbins separately. They normally come with thread and are part of a brand new sewing machine. You usually put the bobbin under the needle in its own compartment on the sewing machine.