All about…fusible interfacing

Three pieces fabrics showing how different interfacings affect them

Here’s the first of an occasional series of posts where we thought it might help to cover some areas where we’re often asked to advise. Over the years we’ve produced a wealth of product descriptions, sew-alongs, social media posts and project blogs. There are lots of common threads (sorry) that twine through them all and we thought it would be a bright idea to gather some of those threads together. So hold onto your collars and cuffs people – I’m kicking off with a perennial favourite that most projects will require you to make decisions about – fusible interfacing.

Fashion trends – and therefore our sewing methods – have evolved over the last decade or two to reflect our preference for more fluid lines. Structure in a garment is still important – lots of us are still partial to a sharply-tailored jacket or coat. However we often tend to use more draping fabrics and we don’t want to lose that lovely movement by affixing an interfacing that will make the garment look or feel like cardboard.

With that in mind, here’s the the inside story of fusible interfacings, including a rundown of our current range, together with images of what exactly it is that they’ll do to a fabric. I’ll also drop in some examples from our sew-alongs and projects to show how they work in action.

Why use interfacing?

Fusible interfacings bring stability, shape and structure to different elements of a garment. However it’s not a case of ‘one size fits all’ – a single garment might require two or three different types of interfacing and the trick is to match the right interfacing to the right job with a specific type of fabric. I know – that sounds like a lot!

Obviously part of that decision-making process is down to knowledge and experience – and I hope this post will help with that. However some of it is down to your preference. That’s why we’ll always recommend trying out interfacings with your fabric to see if you like the result.

Here are a few examples of how fusible interfacing can help…

Fusible interfacings can stabilise fine fabrics and irregular pattern piece shapes – think of neckline or armhole facings in a fine fabric or a knit. They can help a garment maintain its shape – which is why we often apply a lightweight interfacing to hemlines.

Lightweight interfacing applied inside the sleeve hemline on a blazer

An interfacing can also protect and add structure to your fabric. For instance strip of lightweight interfacing is usually applied behind buttonholes, especially fine fabrics used for a blouse; it’s just enough to reinforce the fabric without compromising the drape and movement of your finished garment. If you try and sew those buttonholes without interfacing you risk chewing up your lovely fabric.

Here’s a strip of interfacing inside the buttonhole placket on a blouse

Collars and cuffs on shirts and other garments are usually interfaced – here it’s a case of selecting a weight of interfacing that works for the fabric you’re using – as well as taking into account your taste and how much structure you’d like to have.

Larger areas can be interfaced too – it’s quite common to apply a piece of interfacing to the front of a jacket for example, to add some additional structure. Classic wool tailoring processes would normally involve a stiffer piece of canvas being incorporated – but to retain the drape of a lighter-weight fabric, a fine knit interfacing will add structure without stiffness.

Knit interfacing applied to the entire front of a blazer.

These are the interfacings we currently stock:

Lightweight fusible interfacing (available in Black & White) 90cm width

Use this interfacing for lighter-weight non-stretch fabrics, e.g. cotton lawns, crepe-de-chine, satins, shirtings and lighter-weight wools. It’s a lightweight interfacing (Vlieseline H180/308/9) that is best used for areas of your garment that need gentle structure, including collars and cuffs on blouses and shirts.

Here’s a piece of satin without interfacing…

…and here’s that same satin with the lightweight interfacing applied. You can see that the interfacing adds enough structure to support angular folds as the fabric hangs.

Lightweight fusible knit interfacing (available in Black & White) 75cm width

Use this interfacing for stretch fabrics (including jersey knits) as well as fine fabrics such as satins and lighter-weight wools. It’s a very lightweight interfacing (Vlieseline H609) and when you hold a piece of it you’ll wonder how it can do very much at all. However it will add stability and structure whilst retaining the drape and ease of your fabric. It can be used for areas of a garment (e.g. facings and panels) that need to retain their movement and drape. If you cut it into strips and apply it inside the hemline of a lightweight jersey knit before hemming it will help prevent it from sagging and pulling out of shape.

Here’s what this interfacing does to our satin – it still has much of the drape but with just a little more structure.

Medium-weight fusible interfacing (available in White) 90cm width

Use this interfacing for light- to medium-weight non-stretch fabrics, e.g. suitings. It’s a light-to-medium weight interfacing (Vlieseline F220/304) that is best used for areas of your garment that need gentle but distinct support and structure, including collars and cuffs.

You can see how much structure it brings to our satin here.

This interfacing will work with lots of different types of fabric including wool suitings. Here’s a piece of lighter-weight wool suiting without interfacing…

..and here it is again, with our medium-weight interfacing applied.

You can see how it’s taken away that drape. That’s perfect for a collar or cuffs, but you might not want that amount of structure in a lapel or the body of a garment.

Medium-weight woven fusible interfacing (available in Black) 75cm width

We love using this interfacing on light-to-medium-weight non-stretch suiting fabrics. It’s a medium weight interfacing (Vlieseline G770), best used for areas of your garment that need some additional support or structure, but where you want to preserve some of the drape and movement of your fabric, e.g. soft-tailored lapels or garment panels.

As the name suggests, woven interfacings are manufactured from woven yarns rather than knitted or bonded fibres. They’re a perfect match for fine fabrics, as well as for larger areas of coatings & suitings where you’d like to have some additional structure without stiffness.

Here’s a our blue wool suiting again with the woven interfacing applied. There’s some additional structure, but the fabric still drapes.

IMPORTANT! You’ll need to match the grainline of a woven interfacing to the grainline of your fabric to ensure that you maintain drape & don’t work against it!

What’s the difference between an interfacing and an interlining?

An interlining is a layer of fabric between the outer shell of a garment & the visible lining which will be hidden away inside the garment. Interlinings are cut to the same pattern shapes as the main fabric and are sewn onto the fabric and provide additional warmth or stability. For example a loosely-woven bouclé might have a stable lightweight fabric layer such as organza or lawn sewn onto it, in order to help keep the shape and add a little gentle structure.

Fusible interfacings can also be used – which is what I did with the mohair fabric I used for my ‘Oslo’ Coat. Although I posted it on Instagram I never had the time to blog it, so I thought I’d show you the interlining here.

As you can see, the mohair fabric I used was very loosely woven. To add some warmth & much-needed stability, I interlined all my fabric pieces with our lightweight Vlieseline fusible knit interfacing (H609).

You can see how the oblong of interfacing adds opacity to my mohair

It was touch-and-go as to whether I’d be able to use a fusible interfacing on my mohair as the pile on both sides was so long. I certainly wouldn’t have used it without testing first and it helped that the interlining edges were caught up in my seams so were secured by stitching at the edges too.

The stretch of this interfacing meant that it had an ease similar to that of the fabric. In fact I was amazed at how well it adhered – I only had to re-fuse one corner through the whole of the construction process. You can see how it gave my fabric a gentle ‘springy’ structure here.

Here’s an edge-on view of an interlined piece of mohair – boing!

To protect the texture on the right side of the mohair fabric I used a hand towel with a good pile underneath, folded twice over. Then I could apply the pressure required with the iron for 10-15 secs without pressing the loft out of the mohair.
Although the lightweight interfacing is very fine, by interlining all the outer pieces I added some much needed density to my fabric. I then applied additional medium-weight fusible interfacing to the usual areas of the coat including the collar area and facings.

It all added up to extra cosiness!

Using fusible interfacing – some tips & tricks

  • Always match interfacing weight to the fabric, erring on the lighter side.
  • Use a cool iron (without steam) to press the interfacing onto the reverse of your fabric. Press each area for about 10 seconds.
  • ALWAYS test your interfacing on a spare scrap of fabric first!
  • Garments with interfacing can be washed in the way that you would usually wash the main fabric in your garment. Check the care instructions for your fabric for details.
  • Use a pressing cloth to protect your iron plate from glue.
  • If you’re interfacing small pieces of less stable fabric (e.g. a fine crepe-de-chine), rather than cutting your interfacing exactly to shape, cut a rough-sized piece and lay it over the whole pattern piece. That will ensure you retain the shape of your pattern piece. If you place a piece of greaseproof paper under the pattern piece before pressing to prevent the interfacing from sticking to your ironing board. (Thank you to @sewinsarahjane for that last bit!)
  • Keep your offcuts! They’ll come in useful for small pattern pieces and testing different interfacing weights. But fold them neatly – remember you can’t press them flat…

Thanks for dropping by!

This post is a quick guide which we hope you’ll find useful – although we know there’s always plenty more to be said! If you’ve any questions or suggestions then please – do share them in the Comments below. But thanks as ever to @verykerryberry for nudging me to do this and sharing her wealth of knowledge too!

Finally, we’re continuously updating our range of interfacings so if there’s something you’re looking for that you can’t find, please do contact us and we’ll be on the case 🤓

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