Interfacing – 10 main types ( How to choose the best one for sewing ?)

What is interfacing in sewing? 

Interfacing is a special type of fabric that is used to give support and structure to the cloth it is adhered to. Interfacing gives shape and prevents stretching of fabric out of shape. It is one of the most important aspects of perfect dressmaking.

Interfacing is usually used on garment sections like collars, pockets, pocket flaps, plackets, sleeveless armholes, cuffs, necklines, opening edges, lapels, buttonholes, behind buttons, embroidery, seams, hems, fasteners like zippers, bag straps, bag body- anywhere where there is a need for reinforcement and suitable thickness.

Just some good things that the interfacing does for you

• Reinforces
• Stabilises
• Prevents sagging
• Give shape 
• Neatens edges

Interfacing is usually cut the same as the pattern piece you are adhering it to. If you are using a store-bought pattern, the pattern instructions will tell you all about what type of interfacing to use and how to use it. But if you are making clothes and accessories from self drafted you will need to figure out the best way yourself.

When choosing best interfacing for your project, you should first know the different choices you have and then evaluate it against the fabric you have and the purpose and final appearance of your project.

Types of Interfacing

Interfacing according to how it is attached to fabric

  Fusible interfacing

The fusible interfacing is heat bonded to the fabric by pressing with a hot iron. This interfacing has small dots of glue on one side of the fabric which is melted when heat is applied to the back and the glue bonds the interfacing to the fabric. This is the most preferred interfacing when you want to make a fabric stiffer.

The fusible interfacing can be woven, non-woven or knit. A knit interfacing is mostly fusible and they have a good stretch making it suitable for a variety of purposes. They are supple as well.

The nonwoven fusible interfacing looks like paper. You should follow the grain in this type otherwise you will get wrinkles on the fabric it is attached to.

The woven fusible interfacing can be applied in either direction and feel supple like fabric.

I always interface facing fabric for necklines with a fusible interfacing.

The selection of the right fusible interfacing depends on the fabric you have as well as the place it is applied to and the purpose.

Interfacing is available in Cotton and polyester variations.

Sew-in interfacing

As the name suggests this interfacing is sewn to the fabric. This is usually applied when interfacing should not at all alter the drape or feel of the main outer fabric of the garment; when the garment fabric needs strength and support and you know that fusible interfacing will make the fabric look wrinkly.

For eg napped fabrics like fleece fabric will look different if you try to fuse interfacing on it. Sew in is kept under the main fabric and treated as one.

This type of interfacing is preferred when making garments with very expensive and delicate fabrics like silk, wool etc. Also beaded and sequined fabric cannot be fused with interfacing so a sew-in interfacing is the only way.

Interfacing according to its structure.

  Knit interfacing/Stretch

This soft interfacing has a slight stretch. A fusible tricot knit interfacing is medium weight and is popularly used in dressmaking for fabrics with stretch.

A weft insertion interfacing is knit but has an added crosswise yarn to stabilize the stretch so it has only a moderate stretch. The weft fusible interfacing is very supple and is used to interface anything that needs a soft feel. You can also use it for interfacing silk fabrics.

  Woven interfacing 

A woven interfacing is the most preferred type of interfacing because it behaves just like fabric. A lightweight woven fusible has a good drape and is easy to use. Woven sew-ins are also used especially when sewing seams.

This interfacing has grain ( lengthwise vs crosswise); it should be cut on the same grain as the fabric to which you will be attaching it to. 

  Non woven

This is the most commonly used interfacing when you want a stiff feel – it is available as sew in and fusible and many weights. It looks and behaves like paper. This interfacing sometimes comes with grain and hence needs careful placement.

Non woven sew in interfacing can give great stability to your work. Some even come padded and are great to use for your purse and bag making efforts.

Related post: Nonwoven materials

Other options for Interfacing 

  Fabric /Self-fabric

You don’t always need to buy interfacing for the supporting part. The same fabric as the outer fabric is used to interface; sometimes other fabrics like muslin/ silk organza is used as interfacing. For suede or leather canvas can be used as interfacing. For thin knits, loosely woven knits, laces, illusion or stretch net is used as interfacing. Other fabrics used are swimwear mesh, lightweight tricot or a thin knit fabric.

Net is very good as a backing behind speciality fabrics which needs to keep its drape like sequin fabric.

Instead of sew-in interfacing you can use silk organza or self-fabric the same way as sew in interfacing. Felt fabric can also be used as interfacing in craft projects.

Self fabric or organza is usually used as interfacing for silk fabric. For thick fabrics you can use silk organza as interfacing to avoid too much bulk.

  Hair canvas interfacing

This heavy weight interfacing is used inside jackets to give a stiff feel and structure.

  Fusible Fleece interfacing

This has one side adhesive and the other side fleece which is soft and padded. It is great to give a padded effect for bags, purses, shoulder pads.

  Water soluble interfacing

You can use this type of interfacing when you want to remove the interfacing after you have sewn the project.

  Double sided fusible interfacing

This interfacing has adhesive on either side of the fabric.

Guidelines for attaching interfacing

There are some general guidelines to follow when choosing and sewing interfacing

• Select interfacing which is of the same weight as the fabric you are adhering it to. Interfacing should not be heavier than your fabric
• Ensure that the interfacing is not changing the colour of the fabric. If white colour of the interfacing is showing through a dark coloured fabric use a black interfacing
• Apply interfacing before sewing the seams.
• Interfacing is cut a tad smaller than the fabric it is going to be attached to. 1/8 inch is the standard. This is so that when you press the interfacing to the fabric the interfacing glue will not get into your pressing surface.
• Test fusible interfacing first on a small scrap of the same fabric to know its suitability in terms of weight and the support it will give
• When interfacing facing for garments made of very thin fabrics ( unlined) cut the outer edge of the interfacing 1/4 inch smaller than the facing cloth so that the interfacing will not be visible outside.
• I always mark the neckline markings etc on the interfacing rather than the main fabric or facing fabric

Cutting interfacing

Fusing the full fabric to the interfacing and then cutting pattern pieces or cutting fabric pattern pieces and then interfacing -which is better? Both are viable ways but I prefer to fuse individual pieces. This way you can cut the interfacing smaller so that the glue will not mark the pressing surface. But fusing the whole fabric in one go is convenient though. It is also the best way to cut for slippery fabrics which are difficult to cut.

How to prewash the interfacing

You do not have to pre wash non woven interfacing as they generally do not shrink. But other Washable interfacings do shrink in the wash so it will be better to preshrink by washing before use. But that does not mean you should toss it into the washing machine.

Place interfacing ( the whole bolt that you have) in a tub of water ( cold or warm). Let it remain there for 10 minutes – no stirring or agitating. Take it out and pat dry with a towel. After water is taken out with the towel, hang to dry or lay flat to dry for one whole day.

How to apply a fusible interfacing

Fusible interfacing is better applied to facings than to the fabric of the garment. Fusible interfacing will (may) cause a slightly bubbly wrinkly look to the fabric , especially after a wash ( especially if you have not prewashed the interfacing/fabric)

As said fusible interfacing is cut 1/8 inch smaller than the fabric. Keep the fabric wrong side up. Use the hot iron to heat up the fabric by moving the iron over the fabric .

Keep the glue side ( it will be shiny) of the interfacing on the wrong side of the fabric. Press with a hot iron ( with heat setting suitable for the fabric or if your interfacing comes with directions do follow that). You need to reach the melt point of the glue. You can use steam for better adherence but see that fabric would not spot with water stains. Or you can slightly wet the interfacing to activate the glue. 

Using a press cloth and water spray and firm pressure can give you quick and neat results. Remember to use a dry iron later and use it to finish the process.

Cool the pieces before moving or stitching ; they may come apart.

How to apply a sew-in interfacing

The sew-in interfacing is cut the same size as the piece to be backed ; it is either hand/machine basted or simply caught in the seams as the garment is constructed. When machine / hand basting Pin the Sew-in interfacing to the wrong side of fabric and stitch with a 1/2 inch seam allowance. Trim at the corners if you feel it will lessen the bulkiness at the seams

The problem with sew in interfacing is that if you interface large areas they will hang inside without any support/ binding

Are you having problems with the interfacing

Some things to check are – Is there enough glue on the fusible side or are you using enough heat to fuse?

Common problem – Bulges on fabric surface when using fusible

You have to use the fusible carefully, lest it changes the drape of the fabric. It can make the fabric look wrinkly and with lots of unwanted bulges. This can be prevented by using the iron carefully to bond. The bulging happens when the fabric or interfacing shrinks more when heat is applied. If the heat is adjusted according to the fabric this problem can be avoided.

Related post:How to attach fusible interfacing to fabric; How to add volume to a dress – 10 stiff fabrics for this; Boning; Stabilizers used as backing in Embroidery