Interfacing & Interlining

Interfacing rarely gets the credit, but it's often what separates a homemade finish from a professional one. It's an extra layer worked into a garment or project to add structure, support and stability, stopping a collar collapsing, a buttonhole stretching out of shape or a waistband folding over on itself. Get it right and nobody notices it. Get it wrong and it's the first thing you see.

Most of this range is iron on, which is what the majority of sewers reach for: you place it adhesive side down and fuse it with heat. The woven cotton options are worth knowing about, though. Cotton lawn and cotton voile iron on interfacing move with a woven fabric rather than fighting it, and cotton sits naturally under natural-fibre cloth in a way that a stiff non-woven doesn't. Alongside those sit Freudenberg fusibles in light and medium weights, a stitch-reinforced version for extra stability, fusible knit interfacing for jersey and stretch, a tailor's wool blend for jacket fronts, and Vlieseline Style-Vil foam interlining in both iron on and sew in versions for bags and hats.

Woven, knit or non-woven?

Woven interfacing has a grain, like ordinary fabric, so it should be cut in the same direction as the piece it's supporting. It gives a softer, more natural result and suits shirts, dresses and tailoring. Knit and stretch interfacing moves with the cloth, which makes it the right choice for jersey and anything with give, where a rigid interfacing would pucker. Non-woven has no grain and can be cut in any direction, which makes it convenient for crafts, bags and one-off projects where a slightly stiffer hand doesn't matter.

Iron on or sew in?

Iron on, or fusible, interfacing is quicker and holds itself in place while you work, which is why it's the default for most garment sewing. It needs heat, though, so it isn't suitable for fabrics that can't take an iron, such as some sequins, vinyls and heat-sensitive synthetics, and it can show as a faint line on very fine or sheer cloth. Sew in interfacing is stitched into the seam instead. It takes longer, but it leaves a softer result and is the safer option on delicate, textured or heat-sensitive fabrics.

Choosing a weight

As a rule of thumb, the interfacing should be lighter than the fabric it's supporting, not heavier. Lightweight suits collars, cuffs, facings and plackets on shirting and fine cotton. Medium weight suits waistbands, jacket fronts and mid-weight dressmaking. Heavier interfacings, fusible fleece and foam belong in bags, hats and structured accessories rather than in clothing, where they'd read as stiff. If you're caught between two weights, test both on a scrap: fuse a sample, let it cool completely, then handle it, because interfacing feels quite different once it's bonded and cooled.

Fusing tips

Pre-wash your main fabric before fusing, since fabric and interfacing can shrink at different rates and a bubbled collar after the first wash is difficult to undo. Use a pressing cloth, press rather than glide the iron, and hold it in place rather than moving it around. Let the piece cool flat before you handle it, as the bond finishes as it cools. Heat settings and pressing times vary between products, so check the individual product page rather than assuming one setting works for everything.

More on interfacing

For a fuller explanation of the different types and what each one does, see our guide to what interfacing is and how to use it. If you're making bags, the bag making essentials collection covers the rest of the components.