Jun 29

How To Sew Asymmetrical Hem Using Bias Tape

Bias tape is one of the most luxurious looking finishes that will elevate your garment quality to the next level. While it may seem complicated at first glance, bias tape is actually quite easy and quick to work with, especially if you know the basics of it.

In this article, let's talk about how to sew asymmetrical hem using a bias tape. This same technique will work if you want to finish rounded neckline, sleeveless armhole finish or circular cut hem - anywhere where you have a curve, bias tape finish is a way to go!

This tutorial is created in collaboration with Mettler - manufacturer of high quality threads.

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Mettler SILK-FINISH COTTON 40 Passionate Quilting thread kit

SILK-FINISH COTTON 40 Passionate Quilting set comes in 12 spools of 1000 meter cotton sewing threads

Now let's talk how to hem asymmetrical hem using the bias tape!

How To Sew Asymmetrical Hem Using Bias Tape

STEP 1: prepare bias tape.

If you'd like, for this technique you can buy a ready-made bias tape. However, I do prefer making my own bias tape which can be done from same fabric as my project for an ideal match and it takes just a few minutes to complete.

The 'trick' for making your own bias tape is cutting fabric at 45 degree angle from selvage - this part of the fabric is called bias and it's where fabric has most flexibility. Thanks to that flexibility, we will be able to sew even rounded edges using bias-cut tape.

Bias tape is cut at 45 degree angle from selvage

To cut bias tape, cut 2 wider strap than you want in finished bias tape (for example, if you want to sew 2cm bias tape in finished look, you should be cutting 4cm width strap).

Once the strap is cut, fold long edges towards the middle and press. For this part, I love using bias tape makers, as they make this task much faster and easier. Once the tape is pressed, the bias tape is ready for installing!

Pressed bias tape is ready to be installed

STEP 2: sew around long edge of the tape.

Unfold one edge of the bias tape and position on the right side of the garment, so that the unfolded tape edge goes along the fabric. Using a straight stitch, sew right at the fold line. You want to start sewing by leaving about 1cm from start of the tape, so that we can join edges later. As you sew, navigate the tape so that it follows fabric edge - bend the tape where needed, so that it follows the edge.

TIP: if you want, in this step you can pin or baste stitch the tape, to make it easier to sew on sewing machine.

Follow the hem with bias tape, to mimic the curve of the hem

STEP 3: join tape edges.

Once you sewn around the hem, trim tape ends at the opposite 45 degree angles, put ends together and connect with a short seam.

TIP: one common mistake is joining bias tape edges by cutting straight line down at 90 degree angle, but when we join bias tapes this way, we loose flexibility at seam connection. Instead, we want to maintain that 45 degree edge and cut both edges at 45 degree angle - one tape angle is facing one way, and the other faces the other way. When tapes are joined at this angle, tape maintains flexibility even at seam connection, giving you the result you want.

Instead of joining tape edges at straight cut (top example), join edges with 45 degree cut (bottom example)

STEP 4: understitch the bias tape.

Fold tape and all seam allowance to one side and do understitch, about 1-2mm from the tape connection line, on the bias tape side. This step will help keep bias tape in the garment inside.

Understitching bias tape will help keep it in garment inside

STEP 5: baste stitch bias tape to place.

Fold tape to garment inside, so that on this inside you can see a tiny bit of main fabric and understitch seam. Using hand baste stitch, secure the top of the tape to place.

Baste stitching bias tape will help sew it easier in final step

STEP 6: baste stitch bias tape to place.

Final step is attaching the tape with either invisible hand stitch from garment inside or topstitching from the right side garment.

TIP: topstitch needs to be sewn always same distance from the edge, so make sure that you position width of your topstitch based on most narrow bias tape point.