Choosing the right prewound bobbin is essential for achieving perfect stitch quality and avoiding machine tension issues. Prewound bobbins come in several standard sizes, each designed for specific types of sewing and embroidery machines. Here is a breakdown of the four most common types: M, G, L, and A.
Type M (Jumbo)
Type M bobbins are often referred to as “Jumbo” bobbins. They are significantly larger than standard sizes and are primarily used in longarm quilting machines and high-speed industrial embroidery machines. Because they hold more thread, they allow for longer periods of sewing without needing a change.
Type G (Large)
Type G bobbins are slightly smaller than Type M but larger than the standard home sewing sizes. These are commonly found in specific industrial machines and some older commercial embroidery models. It is crucial to check your manual, as Type G is less universal than L or M.
Type L (Standard Commercial)
Type L is the most common size for commercial embroidery machines (like Tajima, Barudan, and Brother commercial models). Many high-end home embroidery machines also utilize Type L. They are roughly the size of a nickel and are known for their consistent delivery and tension.
Type A (Class 15)
Type A bobbins, also known as Class 15, are the standard for most home sewing machines. If you have a Brother, Singer, or Janome home machine, chances are it uses a Type A bobbin. They have a slightly curved side compared to the flat sides of Type L bobbins.
Always verify your machine’s requirements before purchasing prewound bobbins to ensure compatibility and prevent mechanical damage.
