Fusible, sew-in, woven, non-woven?! There are a variety of different types, weaves and weights in interfacing. So how do you know which one to choose?!
Interfacing, also referred to as interlining, is a type of fabric that is applied to the reverse of fabric. Its purpose is to provide stability and structure to a garment, while also providing strength by reinforcing weak spots and areas prone to stretching. Therefore, interfacing is commonly applied to areas such as collars, cuffs, plackets, necklines, waistbands, and beneath buttonholes.
This post will describe the two main types of interfacing, before identifying the different weaves and weights. Hopefully after reading this you will feel that little bit more confident when it comes to choosing interfacing for your next sewing project.
Wrap up of this article
Tips for choosing and using interfacing
Types
There are two main types of interfacing, iron-on and sew-in.
Iron-on interfacing
Iron-on interfacing, also known as fusible interfacing, adheres to fabric through the application of heat. The reverse of iron-on interfacing will have either rough dots or a shiny appearance. This texture or shine is the adhesive layer, which is fused to the wrong side of the fabric. Therefore, iron-on interfacing is best for fabrics that can tolerate heat, such as cotton or linen. Applying fusible interfacing is a straightforward process.
Cut interfacing to match the size of the pattern piece. Try to ensure that there isn't any interfacing overhanging around the edges as it will stick to the iron or ironing board.
Position the fabric on the ironing board wrong side up.
Position the interfacing on top of the fabric with the glue facing down (i.e. glue side of interfacing facing the wrong side of the fabric) and align the edges.
Press (don't iron) in place for a few seconds using a dry iron or ironing press.
Sew-in interfacing
Just as the name suggests, sew-in interfacing, or non-fusible, is sewn to the fabric. Sew-in interfacing is particularly useful in situations when you want to maintain some of the fabric's drape and/or texture (more natural appearance), or when dealing with fabrics that cannot withstand ironing, such as silk or velvet, or those adorned with beads or sequins.
While sew-in interfacing takes a little more time to apply to fabric, it is also a straightforward process;
Cut the interfacing to match the size of the pattern piece,
Position the interfacing on top of the fabric, wrong sides together, and align the edges.
Pin or baste interfacing to fabric to avoid movement.
Stitch in place, sewing within the seam allowance.
Weaves
Sew-in and fusible interfacing can be further categorised by weave. There are three main weaves of interfacing, including woven, non-woven, and knit.
Woven
Woven interfacing is just like woven fabric, with warp and weft yarns, and a selvedge. Woven interfacing has a grainline, so the pattern pieces should be positioned parallel to it just like any other pattern piece.
Non-woven
Non-woven interfacing is made by bonding or felting fibres together. Unlike woven interfacing, it lacks warp and weft yarns as well as a grainline. Therefore, pattern pieces can be cut in any direction.
Knit
Knit interfacing is created in the same manner as knit fabric, featuring interlocking loops that provides it with stretch and flexibility.This interfacing is ideal for knit fabrics, and lightweight wovens that have stretch and drape. It may be worth investigating which direction of the interfacing has the most stretch and match this to your fabric.
Fabric as interfacing
An alternative to traditional interfacing, is the use of fabric, such as organza or a cotton voile, as interfacing.
Weights
Interfacing also comes in various weights: light, medium, and heavy. When choosing the appropriate weight for a project, a basic rule of thumb is to select an interfacing that is as close to, or lighter, than the weight of the fabric.
Light
Lightweight interfacing provides a small amount of support, allowing the fabric to maintain its natural drape. This weight is ideal for delicate fabrics like silk or lighter cotton.
Medium
Probably the most commonly used weight of interfacing, medium weight interfacing provides support while also remaining flexible. It works with a range of fabrics, such as cotton or linen, and is good for parts of a garment such as collars, cuffs, and plackets.
Heavy
Heavy weight interfacing is reserved for more for specialised projects like bag or hat making, offering substantial stability to the fabric. In dressmaking, it's less frequently used but can be valuable for certain projects where added structure is desired.
Tips for choosing and using interfacing
There are really no hard and fast rules when it comes to choosing interfacing. It is dependent on the type of project and the fabric being used. My best advice would be to test, test, test! I would highly recommend testing different types of interfacing on scraps of the final fabric to ensure it provides the appropriate look and feel you are after.
Here are some more general tips of choosing and using interfacing:
Choose white interfacing for light coloured fabrics, and black interfacing for darker colours.
Always iron the fabric, ensuring it is crease and wrinkle free before applying any interfacing.
If your interfacing has creases in it, pop it in some water, and dry flat.
If using fusible interfacing specifically;
Press (lift and move), don't iron (back and forth) to avoid distorting the fabric.
Allow the fabric to cool before sewing.
For added protection, use a pressing cloth to safeguard both the fabric and iron, especially if any interfacing overhangs.
If working with a slippery fabric, or if you intend to interface multiple small pieces, try interfacing a large piece of fabric first, and then cut out the pattern pieces second.
If using a heavier weight fabric, cut the interfacing slightly smaller when using a fusible type, or trim close to the stitching line when using sew-in, in order to reduce the bulk.
Remember to revisit the pattern markings (e.g. notches) after applying interfacing.
If using fabric as interfacing, remember to pre-wash just as you normally would.
If in doubt, check in with the manufacturer, or the store you brought it from for more information or recommendations.
Please get in touch or leave me a comment. I would love to know if you found this article helpful.
Thanks for reading.
Emma xx
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