Although sewing knit items is not as simple as sewing with fabric, you can sew knitted fabric to repurpose an afghan or make a smaller garment out of a too-large knit garment. The major challenge when sewing knitted fabrics is handling the parts carefully until you secure the cut edges; otherwise, the knit stitches will unravel before you have a chance to bind them with the sewing machine.
Cut apart the sections of a finished knitted garment if you are changing the size of a sweater or similar item. Use scissors or a seam ripper. Work carefully so that you don't pull on the knitting, which could cause stitches to begin unravelling.
Lay the pieces flat on a counter or table. Place a pattern piece on the knitted fabric and pin down one edge in several places. Use the pattern's long black arrows to ensure that the pattern is lying straight on the grain of the fabric. Verify this by folding back the pattern along the arrow and determining if the arrow follows the knitted stitches in a straight line. If not, remove the pins and adjust the pattern on the knitting. Fold the pattern flat and pin it around the edges.
Pin all the pattern pieces, following the black arrows for correct placement. Cut out the pieces, handling them carefully to avoid pulling out the knitted stitches.
Set your sewing machine to a zigzag stitch and make a sample swatch from a knit scrap. Adjust the presser foot's tension for the thickness of the knit material until it no longer stretches the knitted fabric. Zigzag all the edges of the cut pieces.
Pin the pieces together according to the pattern's directions. Use a medium-long straight stitch for heavy knit fabric and a medium setting for lighter knits. Remove each straight pin right before you sew that area; if your needle hits a pin, it could break. It's easy for pins to disappear into heavier knitted fabric, so look carefully as you sew to avoid an unpleasant surprise.
Lightly steam the seams open with an iron that is set to a medium temperature. Do not place the iron on the material since it might permanently flatten the garment, detracting from its appearance.
Choose simple patterns for sewing with knitted fabrics. Tackling complicated collars, bands and trims could be difficult to manage. Easily sew knitted fabrics with a serger, a type of machine that binds and sews at the same time. When using a serger, you do not need to edge the pieces separately. Verify that the pins are placed well away from the areas you will seam.