Sewing machines use two separate threads to sew – a top stitch that comes from a spool and a bottom stitch that comes from the bobbin. All machines have bobbin winders that wind the top-stitch thread onto bobbins. Unfortunately, you must stop sewing while you wind thread for bobbins. Prewound bobbins solve this problem by giving you thread that has been wound to fit your machine’s bobbin case. Instead of winding, you just slip a pre-wound bobbin into your machine’s bobbin case and go.

Bobbins are expensive compared to using thread from a spool. Using them comes depends on how you value your time. Here is one approach:
- Estimate the time it takes to wind bobbins.
- Put a value on that time.
- Multiply time spent by the value of your time.
- Compare the result to the cost of pre-wound bobbins.
How to find out which bobbins style you require: 4 ways
The type of sewing machine determines the bobbins style that is required. If you are unsure of what bobbin style is right for your sewing machine, here are some ways to find out which style your sewing machine requires:
- Get out the instructions – Consult your machine’s manual, or its manufacturer. Both of these sources should be able to confirm for you the size bobbin needed to properly operate the machine.
- Check out your last bobbin – Maybe it has been a while since you have needed a new bobbin for your machine. If that’s the case, try looking around to see if you still have the box or package that the previous bobbin came in. There should be a style listed on it if you do happen to find it.
- Look at this chart – This chart lists over 30 different manufacturers of sewing machines and over 1,000 different models under those brands. All you will need to do is locate the brand and model of your machine. Once you reach that page, you will see the bobbin style listed that corresponds with it.
- Compare bobbins – Try comparing your used bobbin to various new bobbins. Take measurements of your current bobbin, then look for a new bobbin with those exact measurements. Once you find it, just take note of the style listed on the new bobbin’s box so you will have it for future reference.