Form Tape Interfacing

What it is and how to use it

One of the things I love most about sewing is that there are always lots of different ways to do things, which means there’s always something new to learn and try out.

We love Prym haberdashery here at g&g and one of their newer products that we have been trying is Forming Tape Interfacing.

Not to be confused with the popular seam tape interfacing which you might have heard me talk about in my post about sewing jersey neckbands as it can be used to stabilise shoulder seams in stretchy fabric.

What is form tape interfacing?

The difference with form tape interfacing is that it’s made from woven interfacing (rather than no-woven) and its cut on the bias. This means that it’s really pliable and easy to manipulate around curves. You still iron it on to the fabric, just like seam tape interfacing.

The form tape interfacing is really light weight and floaty, so great to use it on lighter weight fabrics and it won’t stiffen or change the appearance of the fabric from the right side.

It has a stabilisng stitch, which is a bit like a chain stitch, running through it. This stitch means that once it’s fixed and ironed onto the fabric, if you put tension on it, the fabric won’t be able to stretch.

When should I use it?

I think the form tape interfacing is great for replacing stay stitching. Quite often sewing instructions will recommend that you stay-stitch the neckline, and sometimes the arm holes, of your garments right after you cut out your fabric. The purpose of it is to stop that curved edge from stretching out as you construct the garment. If the neckline does stretch out, what you might notice is that the neckline becomes quite baggy and flops forward.

Stay stitching is typically down within the seam allowance, so pretty close to the raw edge of the fabric. On lightweight fabric like viscose or cotton lawn, this can be tricky and you might find sometimes the sewing machine has a tendency to eat up the fabric a bit.

So instead, with your iron on a cool to medium setting, simply press the form tape interfacing on the wrong side of the fabric, along the raw edge of the neckline right after you’ve cut out your fabric. The continue constructing the garment as per your patterns instructions.

I've also used it recently when making a top using our sequin fabric. It was great for holding the shape of the neckline. I used it on both the lining and sequin fabric. Just make sure you iron is on a cool setting and check the temperature on a scrap before putting the heat on your actual garment.

I’ve made a little video so you can see it in action – it’s really quick and easy to use and as you’ll see it makes the neckline sit nice and crisp and flat!

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