Sewing button holes is an easy process once you have the basic skills and practise. It's understandable to feel intimidated if you're starting out on your sewing journey. In this post we have put together some helpful tips to sew buttonholes on knit fabrics.
Use a zigzag stitch to sew the buttonhole. This will allow the fabric to stretch without breaking the thread. If your machine has built in button hole stitches, then check your manual as most machine will also have a knit fabric button hole feature (like in the image below - The Janome DKS100 machine has this (stitch 14). It's a stitch designed to work better on knit fabrics but fear not, if you don't have this feature then you can use a regular button hole stitch, just make sure to lengthen the stitch length to around 0.7mm and lower your thread tensions.
Use a stabiliser on the back of the fabric to keep the buttonhole from stretching out of shape. Stabilisers such as iron on Interfacing on the back (wrong side) of the fabric over your button hole line, or if sewing a button placket, add interfacing to the full piece. Make sure the interfacing is a similar weight to your fabric and secure this in place before stitching the button hole.
Make sure you're sewing the button hole with the same machine needle you're sewing the knit fabric with like a ball point needle or stretch needle.
Use a buttonhole cutter or small scissors to carefully cut the opening for the button.
Practice on a scrap piece of knit fabric before sewing the buttonhole on your final project to ensure that you are happy with the results. Make sure the scrap piece is the same amount if layers as your finish product, so if you're sewing through 2 layers, make sure to recreate that on the test piece.
To create a nice clean, neat finish and to stop your fabric stretching or warping whilst sewing, you can place a small piece of paper under your project and sew your button hole with that underneath. It helps to glide your fabric through more easily and once sewn, simply tear the paper away.
When opening the button hole, make sure to pop a pin at the top of the stitch and then use a seam ripper to gently cut that button hole open. The pin acts as a stopper so you don't accidentally cut through it.