Interfacing is a kind of fabric that’s placed into parts of garment to provide shape, support, stiffness, reinforcement, or stability. It’s often used in collars, cuffs, waistbands, lapels, facings, necklines, pockets, and the front bands of shirts.
The back of your pattern will indicate whether you need interfacing and if so, how much.
Choose an interfacing based on the kind of fabric you’re working with and the effect you’re looking to create. Sometimes the back of your pattern will suggest using a specific type of interfacing.
Kinds of interfacing
Interfacing is available in two types – fusible and non-fusible, and in different weaves – woven, non-woven, and knit.
Fusible interfacing is backed with an adhesive that melts with the heat of an iron, bonding the interfacing to your fabric. Fusible interfacing is popular because it’s fast and easy to apply. Always test fusible interfacing first by applying it to a scrap of your garment fabric. This is to make sure it fuses properly to your fabric, that the adhesive doesn’t melt through to the other side, and that you like the degree of stiffness it produces. When applying fusible interfacing, follow the manufacturer’s instructions exactly – instructions should come with the interfacing when you purchase it. Incorrectly applied interfacing can become unglued and bubble up from your fabric, ruining the look of your garment. So why not use fusible interfacing all the time? Because it doesn’t bond well to some fabrics, like those that are highly textured. And it’s not appropriate for napped fabrics like velvet or fake fur – the pressing required to bond the interfacing to the fabric would crush the pile. And it’s not suitable for fabrics that can’t take the heat of an iron like metallics, beaded or sequined fabrics, or vinyl. And it’s not so great for open weave fabrics like laces and meshes because the adhesive would melt through to the other side. Plus, fusible interfacings tend to stiffen fabric more – a look and feel you may not want.
Non-fusible interfacing must be sewn into a garment. It’s usually basted or glued in temporarily, then stitched in permanently. Use a non-fusible interfacing for fabrics that fusible interfacing isn’t appropriate for (see fusible interfacing above for examples) or when you want a softer drape.
Non-woven interfacing is made up of man-made fibers that have been pressed together. The edges of non-woven interfacing don’t fray. And since there is no grain, your pattern pieces can be laid out in any direction. Non-woven interfacing can be used with most kinds of fabrics. It’s available in fusible and non-fusible.
Woven interfacing is made up of fibers that have been woven together. Woven interfacing tends to be stronger and more stable than non-woven interfacing. Woven interfacings are appropriate for most fabrics and are usually sew-in (non-fusible).
Knit interfacing stretches. Use it for knit fabrics. Also, use it for woven fabrics when you want softer shaping or when you want to maintain stretch in the fabric after the interfacing has been applied.
Interfacings also come in different weights – light, medium, and heavy. As a general rule, choose an interfacing that’s slightly lighter in weight than your garment fabric.
Interfacings are also available in different colors – usually white, black, and sometimes gray. As a general rule, choose white interfacing for lighter colors and black interfacing for darker colors.
Choose an interfacing with care requirements similar to your garment fabric. The fiber content of your interfacing does not have to match the fiber content of your fabric. Test the interfacing on your fabric first before applying it to your garment. For fusible interfacing, take a scrap of your garment fabric, fuse your interfacing to it, then let it cool. Examine the piece to make sure the interfacing adhered properly and that no adhesive seeped through to the other side. See if you like the drape and degree of crispness it produced. If not, try another interfacing. For sew-in interfacing, sandwich your interfacing between layers of your garment fabric to see if you like the feel and the drape. Consider purchasing several kinds of interfacing to keep on hand for later projects. This also comes in handy when testing your interfacing. If you don’t like your first choice, you can easily try another. Store fusible interfacing rolled, not folded, remembering that you won’t be able to press out any creases.
There’s debate over whether interfacing needs to be preshrunk. Some recommend it while others believe it’ s not necessary. If you choose to preshrink your interfacing: Launder non-fusible interfacing the way you plan to launder your finished item. Hand wash fusible interfacing. Submerge it in a sink full of warm to hot water for about 10 minutes. Don’t wring the interfacing because it could damage the adhesive and create wrinkles you won’t be able to press out. Instead, roll the interfacing between layers of a towel and blot the water out. Lay it flat to dry - it may stretch if hung. And don’t put fusible interfacing in the dryer. The heat of the dryer could damage the adhesive or the adhesive could damage your dryer. If you choose not to preshrink your interfacing, steam shrink the piece just prior to application (also do this if you plan to have your finished item dry-cleaned). Hold your iron over the interfacing piece and steam it for a few seconds.