Fleece is a knitted fabric with a raised, soft surface on one or both sides. The raised surface traps air, which makes fleece warm for its weight. In apparel, two families are common: sweatshirt fleece (usually cotton or cotton-polyester, brushed on the back) and polar fleece (polyester, brushed and often sheared on both sides).
How sweatshirt fleece is made#
- A looped-back fabric is knitted: a jersey face with a loop yarn tied into the back. This is the same base as French terry.
- The back is brushed (raised): wire-covered rollers pull fibers out of the loop yarn, creating a fluffy pile.
- Some fleeces are sheared to level the pile, or treated to reduce pilling.
Two-thread and three-thread fleeces are common. The three-thread construction uses a separate loop yarn, which is usually coarser and gives more bulk.
Polar fleece#
Polar fleece is usually 100% polyester. It is brushed and sheared on one or both sides, then often treated to reduce pilling. It is light, warm, dries quickly and does not absorb much water.
Typical weights#
| Fabric | Typical GSM |
|---|---|
| Light sweatshirt fleece | About 260 to 300 |
| Standard sweatshirt fleece | About 300 to 350 |
| Heavy sweatshirt fleece | About 350 to 420 and above |
| Polar fleece | About 150 to 350 |
Weights vary by market and buyer. Always specify finished GSM with tolerance.
Common problems#
Pilling#
Raised fibers tangle into small balls on the surface, especially on the brushed side and in cotton-polyester blends where the strong polyester fibers hold the pills. See pilling and pilling testing.
Shedding#
Loose fibers from brushing come off in wear and washing, and can transfer to other garments. Good brushing control and finishing reduce it.
Shrinkage#
Cotton-rich fleece can shrink significantly, especially in length, if not stabilised. Test before cutting. See fabric shrinkage.
Uneven brushing#
Patches of different pile height or color show as shade differences. Check across the width and between rolls.
Sewing fleece#
- Use needle sizes suited to the fabric thickness, with ball point needles for knits.
- Overlock seams and coverstitch hems are standard; flatlock is used for flat, comfortable seams.
- Seam crossings (hood to neck, sleeve to side seam) get bulky; check needle deflection and skipped stitches.
- Clean machines often: fleece produces a lot of lint.
Consumption#
Fleece is bought by weight. Body fabric and rib (cuffs, waistband) are usually costed separately. Use the hoodie consumption calculator.
Specifying fleece#
- Construction (two-thread or three-thread, face and back yarns)
- Composition
- Finished GSM and width
- Brushed side (back only, both sides)
- Anti-pill finish if required
- Shrinkage, pilling and color fastness requirements
Related guides#
- Single jersey fabric: the jersey face that fleece is built on.
- Different types of knit fabrics: where fleece sits among the other knitted fabrics.
- Knit fabric consumption: how to calculate body fabric and rib for hoodies by weight.
Frequently asked questions#
Why does fleece pill more on the inside? The brushed side has many loose fiber ends, and the inside rubs against the body and other layers. Anti-pill finishes and good yarn quality help.
Is polar fleece the same as sweatshirt fleece? No. Polar fleece is usually 100% polyester, brushed and sheared on one or both sides. Sweatshirt fleece is usually cotton-rich with a jersey face and a brushed back.
How do I stop fleece shedding on other garments? Shedding falls after the first washes. Good brushing control, shearing and a pre-wash at the finishing stage reduce it. Advise consumers to wash fleece separately at first.
Does brushing change GSM? Brushing raises fibers and can remove some loose fiber, and it changes thickness and hand feel. Measure GSM on the finished, brushed fabric.