Joining Strips of Bias Trim

Bias trim, a.k.a. "bias tape" is a wonderful notion used to finish blankets, trim out garments, used for straps, and for many many other craft uses. When cutting bias strips, you have to join all these strips together to form one long strip in order to complete your project.  It's no fun when you start your project and realize that you don't have enough bias strips.  Save the frustration and make the exact amount of bias trim needed by joining all the strips together at once.  You would think that the easiest way to join these strips is to use the traditional "vertical" sewing method of sewing them right sides together.  You could do this, however, you would end up with a very thick seam that will be very difficult to sew...what a SEWING MESS!!!!  You do want to sew them with right sides together, but you will not do it the "normal" sewing way.  Look below to see the "correct" way to sew these strips so as not to have excess bulk. To do this correctly, you need to make sure that all of your strips are the exact same size in width...this is VERY IMPORTANT! If you don't want to cut them yourself, you can purchase a bias strip maker.

Once you have all your strips cut the same width, you now want to prepare them for joining. Work in sets of 2 strips at a time. Start with the first strip...cutting it on the diagonal. Once you have cut the first strip,
you can lay the cut strip on top of the next strip for alignment.  You want the cut strip to overlap the uncut strip.

Using the cut strip as a pattern, you want to cut this strip based upon the diagonal of the cut strip.
When the second strip is cut, it should match up with the first strip like a puzzle piece. Now you are ready to sew the two strips together.
In general sewing, you would sew a 5/8" seam allowance, but when joining bias strips, you will sew a 1/4" seam allowance.
Now that your seam is sewn, you notice that the seam is on a diagonal rather than a straight line. This is exactly what you want. It allows the bulk of the seam to be distributed diagonally, making the seam less bulky.

To insure there is no excess bulk, you want to "butterfly" the seam (press it open). You can do this with the iron, or you can finger press the seam open.
With the seam pressed flat, it is now ready for the double fold.

When you turn both edges inward, and fold them over, you will not have all the excess bulk that you would have if you had sewn the strips vertically, because the seam has been spread out.
Now that your bias strip is folded, it can be sewn together.  If you are attaching the strip to a garment, you would sandwich it around the garment.  If you are using the strip for a strap, you would simple sew a top stitch to catch both side of the bias trim.  This technique is a simple and elegant way to give your project a professional look.  I hope this tip has been helpful...Happy Sewing!

Click below for a video tutorial on how to join strips of bias trim.