Short answer: you usually shouldn’t — and if you do, you have to be careful. Fleece and fusible interfacing don’t get along for two reasons, and there’s almost always a better choice. Here’s what’s going on and what to use instead.
Why fusible interfacing struggles on fleece
- Fleece is heat-sensitive. It’s polyester, and the iron temperature needed to melt fusible glue can flatten the nap or even scorch and melt the fleece. That soft loft is the whole point of fleece, and fusing can ruin it.
- The nap fights the bond. Fusible glue needs a smooth surface to grip. Fleece’s fuzzy, lofty pile gives it very little to stick to, so the bond is weak and tends to peel.
Use these instead
- Sew-in interfacing. For structure on fleece (cuffs, plackets, bag pieces), a sew-in interfacing avoids heat entirely and is the reliable choice.
- Often, no interfacing at all. Fleece already has body and doesn’t fray, so many patterns don’t need interfacing on it in the first place.
- Note that “fusible fleece” is a different product — that’s a fusible batting you bond to other fabric for padding, not interfacing for fleece.
If you really must fuse to fleece, use a low-temperature fusible, always with a pressing cloth, press from the interfacing side, use a press-and-lift motion (never slide the iron), and test on a scrap first — fleece varies a lot, and some will melt before the glue activates.
Frequently asked questions
Will fusible interfacing stick to fleece?
Poorly. The fuzzy nap gives the glue little to grip, so the bond is weak and peels. A sew-in interfacing is far more reliable on fleece.
Does fleece melt under an iron?
It can — fleece is polyester and the heat needed to fuse interfacing may flatten the nap or melt it. Always use a pressing cloth, low heat, and test a scrap.
What interfacing is best for fleece?
A sew-in interfacing, because it adds structure without heat. Often fleece needs no interfacing at all, since it already has body and doesn’t fray.
