Choosing Interfacing

CHOOSING INTERFACING

Selecting the interfacing you should use in your project can be a challenge and unfortunately, I find that the big box fabric stores don’t know their interfacings very well! The most common interfacing incorrectly recommended - is very firm heavy weight interfacings.  So firm that they would suit bag making projects - not dresses and coats.

So here is some information to help you understand interfacing.

Why?

Simply put, interfacing adds structure, so for example - it’s going to make your collar firmer.

• Interfacing is often referred to as interlining as well.
• Non-fusible, means you will need to sew-in/baste it to your fabric pieces.
• Fusible interfacing irons on. One side is covered in tiny “glue” dots. 

Types 

• Non-woven interfacings - won’t have a grain line.
• Woven interfacings - do have a grain line and you need to line this up with the fabric’s grain line.
• Knit / stretch interfacing - you’ll need to get knit interfacing when you are sewing with knit fabrics. 
• You can even get your hands on wash away interfacings.

Always follow the pattern envelope directions for supplies to stay (hopefully) out of too much trouble.

Weight

Interfacings come in a variety of weights (unfortunately, the colours are on the other hand are limited to white and you may be lucky enough to find grey).

In most circumstances you want to match the weight of your interfacing to the weight of your fabric.

In a nutshell:

• Medium to heavyweight - if it is loosely woven, it will suit tailoring in heavy weight jackets and coats.
• Heavyweight Firm - if it holds it form like a cereal cardboard box, you should keep it for crafting projects. Or perhaps you are looking to create a super structured garment that will maintain your personal space for you.
• Light to medium weight - Suitable for collars, cuffs, jackets.
• Light weight - Suitable for dressmaking blouses, dresses.

Pre-Test

You should always do a pre-test on a small sample of your fabric.  Some fabrics may not accept fusible interfacing and you’ll need to switch to sew-in / non-fusible interfacing.

Technique

• Choose your iron's wool setting with steam.   
• Use a pressing cloth to protect your iron and your fabric.
• You can use a damp pressing cloth and a dry iron instead.
• Put the wrong side of the interfacing to the wrong side of the fabric. Press from the right side of the interfacing.
• Fuse each area for 10-15 seconds, overlapping your iron to avoid missing areas.
• To avoid “heat shock” which causes puckering, you should pre-heat the fabric then fuse.
• Heavy fabrics and heavy interfacings may need a combination of heavy steam and a damp pressing cloth with a longer fusing time (up to 30 seconds). Additionally, you may need to follow up by fusing from the right side.
• If your pattern speaks about Block Fusing, it simply means that you are going to fuse the interfacing to all of the fabric before you trace off and cut out your pattern pieces. It there are only a couple of pieces requiring fusing, you will cut out the pattern pieces in both the fabric and fusing and apply directly. Let your pre-test guide you on what will get you the best results.

Alternative

• In a pinch: you could baste another piece of the fashion fabric to pieces requiring interfacing. The success of this will totally depend on the amount of structure you want.

Brands

Here are some brand names of fusible interfacings you can request and sound like a smarty:

• Sheerweft - fine knit and ultra smooth. Ideal for semi-sheer fabrics, whites and light colours because it has a fine texture which will not shadow through.
• Textureweft - fine textured knit with crinkly fusing surface.  Ideal for interfacing loosely woven fabrics as it adds soft body. The crosswise stretch makes it suitable for texturised knits with moderate stretch.
• Whisperweft - medium weight with rayon. Idea for light to medium loosely woven fabric that require more support. It is best suited to fabrics with high natural fibre content that are hand washed or dry-cleaned.
• Armoweft - Heavier weight with dense rayon yarn. Idea for use under collars, cuffs and jacket fronts. Idea for heavier fabrics like wool flannel, tweeds and coatings. Best used on garments to be washed or dry-cleaned.

SewParts also have an extensive range of interfacings, including; fusible, non-fusible, tear-aways, wash-aways, all weights, and greys.

*Much of this information has been compiled from McCall’s Australia’s Interfacing Fact Sheet.