Making Continuous Cut Bias Tape
The ability to make your own bias tape is a bit of a sewing super power. We use bias tape in many sewing projects: finishing edges on quilts, potholders, and garments. It is quite handy to be able to make your own bias tape out of any fabric you choose, in any size you need.
This tutorial will show you how to make bias tape in the easiest and most efficient manner, which is the technique called “continuous cut bias tape.” Get ready to increase your sewing powers.
What is Continuous Cut Bias Tape?
Fabric has a grain, like wood. Fabric grain is determined by the direction of the weave of the threads that make the fabric. The threads go lengthwise or crosswise, perpendicular to each other. When fabric is cut along the direction of the woven threads, the cut is said to be “on grain.” When fabric is cut at a 45 degree angle to the grain, it is said to be cut "on the bias." The terms "bias tape" and "bias binding" may be used interchangeably.
Bias tape is a narrow length of fabric cut on the bias. It can be made by cutting strips of fabric on the bias and then sewing the strips together. Or, the fabric can be prepared in such a manner that it is sewn and marked before it is cut. Then the strip is cut continuously from beginning to end, and finished by winding it into a small roll. This technique for continuous cut bias tape is what we will learn here. It is a little bit of sewing magic to turn a flat rectangle of fabric into a neat bundle of bias tape, ready for use in your project.
Start with a Fat Quarter
Fabric stores sell precut fabric in a size called a “fat quarter.” Most quilting cottons are about 42” wide. If you purchase a quarter of a yard, the piece will measure 42” wide by 9” long, which may not be the most convenient shape you need. Another way to cut a quarter yard of fabric is to cut half a yard (18”) and then cut it in half again, along the center line of the width, so there are two pieces, each measuring about 18” by 21”. Each piece is a fat quarter, and it is a convenient size for many small projects. It is a good size and shape to demonstrate the making of continuous cut bias tape.
Prepare the fabric
I always launder my fabrics before I sew with them. Wash, dry and iron the fabric. Then square up the piece, which means trim the edges so that all the corners are 90 degree angles. I used a vertically striped fabric so you can more easily see the direction of the grain. The grain of this fabric is the same as the direction of the stripes.
Cut off a triangle
Fold one corner of the fabric diagonally into a triangle as shown in the photo. The fold will be at a 45 degree angle. The edge of the triangle should be even with the edge of the rest of the piece of fabric. Iron the diagonal fold. Cut the triangle off along the fold.
Position the pieces
We are changing the shape of our fabric into a parallelogram, putting the bias cut edges on the outside of the shape. The picture below shows the fat quarter cut along the fold made in the previous step. Move the triangle on the left in the photo below, to the right.
The photo below shows the triangle moved from the left to the right. The bias edges will be on the outside of the shape. Sew the pieces together using a 1/4" seam allowance. Press the seam open. Now we have a parallelogram, with two bias edges and two on grain edges.
Marking the Fabric
Marks are made parallel to the bias edges, on the wrong side of the fabric. Using a ruler and pen (I use a regular ball point pen for this) mark lines in the width of bias tape you need. In this example, the lines are marked for 2” wide bias tape. These lines will eventually be the cutting line. The space above the last marked line will probably not be the width you need, so cut the fabric along the last marked line and discard the small cut off piece. Mark a line 1/4” in from the "on grain" edges. This line will help you place the pins properly in the next step.
Prepare for the Second Seam
The next seam will join the on grain edges. Place the fabric parallelogram on your work surface, right side facing up, with the on grain edges on the right and left. Fold the right and left edges of the shape in toward the center, and offset the top edge as pictured below. Your piece may not look exactly like this one since measurements vary. The important detail is to offset the top edge, which will be where you start cutting the bias tape after the seam is sewn. You are making a tube of fabric. The lines you drew along the bias will form a spiral around the tube.
Pin the on grain edges together, placing the pins through the intersections of the marked lines, as pictured below. This seam is a little tricky because it spirals around the tube of fabric you are making. Use lots of pins and take your time. Sew the seam and press it open.
Place pins through intersections of drawn lines
Cut the Bias Tape
Cut along the marked line that spirals around the tube, and the tube turns into a length of bias tape.
Folding the tape
The last step in preparing your bias tape is to fold it into the form you need. One way to fold bias tape is to use a tool, called a “bias tape maker,” which should more accurately be called a “bias tape folder” because the tool helps fold the bias tape, which is already made. To use the tool, feed the strip of fabric into the more open end of the tool, and iron the fabric as is comes out of the other end, as pictured below. This type of bias tape is called "single fold bias tape." If you fold single fold bias tape in half lengthwise, it is called "double fold bias tape." Confusing and not important to remember.
For quilts, I use French binding, which is bias tape folded in half lengthwise. For this type of bias tape, don’t press the fold. Just coil it into a neat roll.
Making 2 1/2” wide bias tape from a fat quarter of fabric will make about 118” of bias tape, which is the perfect size for making two potholders using this tutorial. If the width is 2”, you will have about 160” of bias tape, which is enough to trim the edges of this apron. The finished length will vary depending on the exact measurements of the fat quarter you use.
Now you can confidently make the perfect bias tape for your own project.
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