What makes interlock fabric so special? Regular jerseys have an interconnecting series of loops, with smooth knit stitches on one side and bumpy purl stitches on the other. Using hooks and combs to knit the pieces together, the result is a fabric that lays flat. But when you want to make a dress, sweater, or other garment, you'll need to use a slightly different method. For this type of fabric, two layers of jersey are bonded together and an additional thread is introduced into the mix.
When sewing interlock fabric, you'll need to use a machine that can handle this type of yarn. You can use a regular sewing machine or a to sew interlock. If you have a or cover stitch machine, you can probably use this technique. If you want to avoid stretching the fabric, you'll need a triple-straight stitch for best results. Basically, any type of stitch will work with interlock.
You can find interlock in several weights. The heaviest and most durable version is a 3-ply knit. If you're sewing with a regular machine, a 2-ply thread will work. A serger can be more difficult to use, but a home sewing machine will work just fine. A triple-straight stitch is a good choice for sewing interlock. A double-straight stitch will also give it some extra strength and elasticity.
If you're using , you should buy a thread that can handle the high friction. It's much better than a regular sewing machine that can't cope with the stress of the stitches. For this type of fabric, you should use a serger or cover-stitch machine. Try to use a triple-straight stitch, as it adds elasticity and strength. When sewing with a regular machine, you should use a zigzag stitch, or a basic straight stitch.