Croft Mill

What Is Interfacing? The Different Types & Its Uses

What Is Interfacing? The Different Types & Its Uses

Interfacing is a fabric which is used to give support and structure to the material it is adhered to.

What type of interfacing is best?

Interfacings come in 2 main types: fusible (iron on) and sew in.

3 different weaves: non-woven, woven and knit.

And 3 different weights: light, medium and heavyweight.

Fusible interfacing is the easiest to use because it has an adhesive on one side which bonds permanently with the fabric when pressed with an iron. Most sewing patterns will have instructions as to which pieces need interfacing.


What is sew in interfacing?

Sew-in interfacing is another layer of fabric which is hand sewn on to the main fabric to give it rigidity.

Add another layer of fabric to the main fabric to achieve a more structured end result.

Held in place by hand stitches it gives a natural shaping and drape as there is less “stiffness” to it.

Sew-in Interfacing - fabric roll

What is non-woven interfacing?

Non-woven interfacing is made by bonding fibres together. It has no grain, can be cut any direction and won’t fray.

1M-10M Blue Non Woven FabricNon Woven Interfacing Mask image 1

What is woven interfacing?

Woven interfacing has a lengthwise and crosswise grain. In other words match the grain of the interfacing, with the grain of the piece of the garment to be interfaced. This will enable the two layers of fabric work together with no distortion.

Lightweight iron on cotton lawn interfacing

What is knit interfacing?

Made by knitting the fibres together, it has an amount of stretch in it. Use with jerseys and other stretch fabrics as it will stretch with the garment. However, add a woven interfacing to a knit fabric, and the fabric’s stretch properties are reduced. In conclusion, only use a stretch interfacing on stretch fabric.

Interfacing - Traditional Interlining

When should interfacing be used?

It reinforces fabrics – button strips on a button up shirt, makes it easier to sew good buttonholes.

Stabilises flimsy fabrics to allow you to make a shaped collar or cuff.

Used in applique projects, interfacing allows you to draw and cut your design out easily and gives the design a rigidity which works perfectly with satin stitching.

Interfacing is used to stabilise the edges, when repairing a hole or tear in the fabric.

What weight interfacing should be used?

Interfacing should be the same weight as the fabric, or a bit lighter.

Do NOT use a heavier weight interfacing than the fabric, because the garment won’t drape well.

For medium weight fabrics, use medium weight interfacing.

Knit fabrics, use medium weight knit interfacing.

With very sheer or lightweight fabrics, use a second layer of the main fabric as a form of sew-in interfacing!


  • Use a knit interfacing with jersey or stretch fabrics.
  • Use non-woven interfacing for most tasks (other than when using jersey or stretch fabric) however, only consider woven interfacing for particularly fine materials such as sheers and silks.
  • Match the interfacing colour with the fabric. Black interfacing for dark colours and white for light colours.
  • A medium weight is generally good for most things. The pattern will recommend the best interfacing.

DO NOT use fusible (iron on) interfacing with...

  • Pile fabric like velvet or fur as it flattens the pile.
  • Fabric that will melt or distort with heat – sequins, plastic, vinyl.
  • Very textured fabrics with uneven surface – glue will not stick.
  • Because fabrics like lace, tulle and other mesh-based material have little or no “substance” for the glue to adhere to, fusible interfacing can be difficult to use.

How to apply a fusible (iron on) interfacing


  • Apply fusible interfacing to facings rather than to the fabric of the garment.
  • Fusible interfacing can cause the fabric to have a wrinkled look as a result of being washed.
  • With the fabric wrong side up use a hot iron to pre-heat the fabric.
  • Place the glue side (it is shiny) of the interfacing on the wrong side of the fabric. Press with a hot iron and pressing cloth.
  • Make sure the heat setting is suitable for the fabric.
  • Use steam for better adherence. A pressing cloth should be used to prevent water marks.
  • Above all press firmly down on the fabric to secure, let the fabric pieces cool down before using.

How to use sew-in interfacing

  • The interfacing should be cut to the same pattern as the piece it is going to back.
  • As the garment is being constructed, hand sew or baste the interfacing into it attaching it carefully.
  • Pin the sew-in interfacing to the wrong side of the material and stitch with a 1/2 inch seam allowance.
  • Trim at the corners to lessen the bulkiness at the seams.
  • Give the interfacing as much support as possible to prevent it from just hanging.
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