It’s true that it’s generally easier to just buy a package of pre-made bias tape, but we don’t sew our own clothes because it’s easy, do we? I like to make my own bias tape most of the time because I can get a perfect color match and I can match the weight, hand, and fiber content of the main fabric. Pre-packaged bias tape is generally a cotton-poly blend and is pretty stiff. That might be just fine if you’re putting a Hong Kong finish on the seams of a denim jacket, but if you have a cotton voile or a silk crepe de chine blouse, it’s going to add a stiffness that you won’t want.
What is bias tape?
Bias tape is simply a strip of fabric that is cut on a 45 degree angle (for a “true bias” because it has the most mechanical stretch). If you’re used to working with pre-packaged bias tape, you can make your own with the following measurements:
Single Fold Bias Tape: Cut at 1″ wide with each edge folded under 1/4″ to make a finished width of 1/2″
Wide Single Fold Bias Tape: Cut at 1 5/8″ wide with each edge folded under a generous 1/4″ (or scant 3/8″) to make a finished width of 1″
Double Fold Bias Tape: Made as Single Fold Bias Tape and then folded again in the middle for a finished width of 1/4″
Wide Double Fold Bias Tape: Made as Wide Single Fold Bias Tape and then folded again in the middle for a finished width of 1/2″
Bias Hem Facing: Cut at 2 5/8″ wide with each edge folded under a generous 1/4″ (or scant 3/8″) to make a finished width of 2″
What fabric do I use for bias tape?
Stylistically, it’s up to you whether you want your bias tape to match your main fabric or contrast. As a general rule, I like to use lightweight cottons like voile or lawn since it makes a lightweight bias tape that is easy to make and press but won’t change the hand of lighter fabrics. If your main fabric isn’t too lightweight or drapey then a quilting weight cotton broadcloth is a nice choice and very easy to work with. You can also make your bias tape from much drapier fabrics like silk crepe de chine or charmeuse or rayon viscose. It can make a beautiful effect but it’s much harder to press accurately as it slips around.
How do I make bias tape?
To make your own bias tape, use the straight edges to determine the 45 degree true bias of the fabric and cut along the true bias. You can do this by using a large quilting ruler with a diagonal marked on it. Lay the diagonal so it is along your straight grain (the selvedge) and the edges of the ruler will be on the bias. I chalk along the bias line and then cut along my chalk.
Alternatively, you can fold the fabric so that the two straight edges are together and cut along the diagonal fold.
After making your first cut, measure, mark, and cut along an even distance from the edge of the first cut.
How do I join bias tape?
If your single piece of bias tape isn’t long enough it’s easy to join a second strip to lengthen the bias tape. Overlap the bias strips at a 90 degree angle so they make an L. Draw a line along the diagonal of the square that they overlap makes and sew along that line.
Cut off the excess fabric.
Press the seam open.
Making Bias Tape from Bias Strips
Once you have made your strips of bias fabric you may want to press them into pre-made bias tape (Note: This isn’t always the case. For example, the Ultraviolet Tee has instructions for finishing the neck with bias fabric without first folding it into a tape.) You can buy bias tape makers that are quick and easy to use. You thread the fabric into the tape maker and it helps to tuck it into the right fold for you as you press it on the other end.
Sometimes the simplest methods are best and I get the best results making bias tape with a cardboard template. All you have to do is cut a piece of cardboard the width of your finished tape and use it to press the edges over.