Fusible interfacing gives strength and stability to fabric without making it evident that you are using another layer. That is, if it is correctly applied, and perfectly bonded.
In worst-case scenarios, the interfacing can cause bubbling on the fabric surface; it can come off when handling, washing, or change the fabric’s drape—all in all, a disaster in the making. But let us be optimistic.
When done right, fusible interfacing makes the fabric behave the way you want it to – a slippery fabric can be cut easily, a fine fabric will have enough stability to hold on its own, a weak fabric can be strong enough to withstand all pressures, a stretchy area of a garment can withstand getting stretched out of shape, etc.
It is used in all places where you need some reinforcement – collars, on buttonhole plackets, along zipper openings, hems, flaps, pockets, yokes, and any other parts of the garment which need stability. When sewing necklines a fusible interfacing is a given – it is applied to the back of the neckline or on the facing.
The entire hem can be backed with the fusible interfacing to give a beautiful flat hem. It is also added sometimes to seams to give extra strength. For eg. on top of a vent, at the tip of a v neckline.
Types of fusible interfacing available. Which fusible interfacing to use with which fabric?
There are 4 types of fusible interfacings. Woven, non-woven, knit and weft insertion. Knit interfacing is also called tricot interfacing. A knit interfacing with cool-fuse properties can be used for fabrics that do not take heat like lycra/spandex.
The fusible interfacing comes in different weights and drapes. A very light weight knit fusible interfacing( sheer types) can be used with thin fabrics. Same with textured fabrics like shirred fabrics – use the lightest weight tricot fusible possible.
If you are using knit fusibles, try to match the stretch of the interfacing with the stretch of the fabric.
Read more on choosing the correct type of interfacing.
How to apply fusible interfacing rightly?
The fusible interfacing is applied such that it is permanently bonded to the fabric. The resins on the material bond to the fabric when heat is applied along with the pressure of pressing with an iron.
If you do not want the front of the garment to change in the drape and hand you can apply the fusible interfacing to the facing pieces.
Some rules to follow when fusing
☝ Do not move the iron in up and down motion. Press down.
☝ Always choose fusible interfacing which is lighter in weight than the fabric you have.
☝ Heat, pressure, moisture and time duration of pressing can alter the hand of the fabric in a variable fashion. Always test fuse on a test fabric piece for consistent success with the fusing.
☝ Protect the soleplate of your iron as the gum can stick to the plate, clogg the steam holes…. Use a pressing cloth.
Step 1. Prewash the fabric and the interfacing.
Most people skip this step – but this gives the fusible interfacing the hate it does. Instead of washing it yourself, you can buy pre-shrunk interfacing. Ensure that you are washing in cold water to wash the interfacing
You can use the steam function on your iron to shrink the interfacing.
Step 2. Remove all wrinkles from your fabric before cutting.
The wrinkles on the fabric, as well as on interfacing, can cause the interfaced fabric to look puckered. So press the area to be interfaced properly before you apply the interfacing.
Step 3. Cut the interfacing
If you cut the fusible interfacing with the grain it will give you steady strong support but if you cut the interfacing on the bias it will be more pliable.
Step 4. Heat up the iron properly for interfacing
This is necessary for fusible interfacing to work. Wait till the iron is heated to its maximum for the fabric in hand. Silk/wool setting is used for non-woven interfacing.
Use only dry setting.
Keep the interfacing with the shiny coated side facing the back of the fabric.
Step 5. Use a cover
Actually an iron sole plate is preferred to a teflon coated sole plate – but what to do, if you have only this. You can use a cover. This refers to using an ironing table cover made of cotton as well as using a cotton pressing cloth, when necessary.
A pressing cloth can prevent the interfacing from sticking to the iron. If you do not want the front of your fabric to be destroyed (especially if it has texture) keep a terrycloth towel on the ironing board and place your fabric with the surface down on it.
Step 6. Test-fuse
If possible use a fabric scrap to test-fuse. This is optional but you will be better off if you do this- choose a scrap to test the heat and how the interfacing will fuse.
If you are using woven or knit interfacing it will have a grain – you have to match the grain of your interfacing to the grain of your fabric- also ensure that the stretch of the interfacing is matching the stretch of the fabric.
Step 7. Press. do not iron
Pressing means you bring down the iron and then take it straight up and repeat this. Ironing means back and forth motion. Dragging the iron over the fabric will cause the interfacing to stretch and cause puckering, so pressing is recommended for fusing.
Press for 10 seconds, take it up; then come down to the next position, hold down for 10 seconds. That is how it goes. You may have to do this more than 2-3 times for the bonding to be done properly.
If you made some mistake in applying, or you see an unwanted wrinkle, lift off the interfacing while it is still warm and then reapply.
Step 8. Keep aside until cool
If you use the interfaced fabric immediately after fusing, it can come apart or pucker. Wait till the pressing heat is completely cool before using it for sewing or cutting – this is usually done in half an hour
If you have fusible interfacing applied anywhere in our garment, it goes without saying that you should not use hot water to wash it.
Which fabrics do not take fusible interfacing?
The fabric should have a smooth side for the interfacing to bond – this is a very important rule in using the fusible interfacing. It is applied to the smooth side of fabrics. So you cannot apply this interfacing to fabric with unevenness on both sides like a burnt-out velvet or, beaded, and sequined fabric.
You cannot apply it to open weave fabrics like mesh, gauze, eyelet cotton, lace, net and even for semi-sheer fabrics like cotton lawn.
You cannot apply fusible interfacing on fabrics with pile as the fusible will flatten the pile of the fabric (Deep pile velvet, Chenille, fake fur etc.); Also textured fabrics like puckered fabrics or shirred fabrics.
If your fabric is not suitable to be pressed with a hot iron it is not suitable for the usual heat bond fusible interfacing. Eg. Leather, fake leather, coated fabrics.
You will need a sew-in interfacing for these. Also check out the Guide to Interfacing for Beginners