Fabric Finishes: Mercerized, Enzyme, Peached

Scheduled article — part of the Fabric Education series.

Two fabrics with identical construction can feel worlds apart after finishing. The loom or knitting machine decides a fabric's structure, but finishing decides its hand-feel, lustre, surface and performance — often the difference between a fabric that's merely acceptable and one that sells the garment. Here are the finishes buyers request most, and what each actually does.

Mercerizing

Treating cotton under tension with caustic soda increases strength, lustre and dye uptake. Mercerized cotton looks richer and takes deeper, more even colour.

The treatment permanently swells the cotton fibre into a rounder cross-section, which reflects light more evenly — that's the lustre — and opens the fibre to dye, so you reach deeper shades with less dyestuff. Dimensional stability improves too. You'll meet it most in premium poplins, sateens and polo piqués. It adds cost, so specify it where the visual payoff is real: solid-dyed shirting and deep, saturated colours.

Enzyme wash (bio-polishing)

Enzymes gently remove surface fuzz, leaving a smoother, cleaner face and a softer hand — without the harshness of heavy chemical treatment.

Cellulase enzymes trim away protruding fibre ends, which does two useful things: it reduces future pilling (fewer loose ends to tangle) and cleans the surface so colours read brighter. Expect a small strength and weight loss — typically 2–5% — which a good finisher accounts for when targeting your final GSM. For cotton knits destined for premium basics, it's close to a default upgrade.

Peaching (sueding)

Fine abrasion — emery rollers or carbon brushes — raises a whisper-soft, brushed surface: the "peach-skin" hand popular in premium shirting, bottoms and overshirts.

Peaching mutes colour slightly and relaxes drape. Because depth of abrasion varies, agree the depth of peach on a physical standard — "lightly peached" and "heavily sueded" are different fabrics — and check pilling after finishing, since a raised surface pills more readily than a clean one.

Others worth knowing

• Softening — silicone or cationic softeners for a plush hand-feel
• Water-repellent — durable water-repellent (DWR) for outerwear and technical use
• Anti-pilling — to keep knits looking new
• Calendering — pressed lustre and a flatter, closed surface for tightly woven fabrics

At a glance

Finish	Main effect	Best for	Watch out for
Mercerizing	Lustre, deeper colour, strength	Shirting, piqués, sateens	Added cost
Enzyme wash	Cleaner face, softer hand, less pilling	Cotton knits	2–5% weight/strength loss
Peaching	Brushed peach-skin surface	Shirting, bottoms, overshirts	Pilling; agree depth on a standard
Softening	Plusher hand	Almost anything	Can affect sewability and absorbency

Specifying finish

Finish is part of the brief. "Cotton twill ~240 GSM, peached" tells us far more than construction alone — and stating GSM after finishing removes a common ambiguity, since washing and brushing both change weight. Approve hand-feel on a physical swatch rather than a description, keep the approved swatch as the bulk standard, and confirm that fastness and pilling are tested on the finished fabric, not the greige. We coordinate finishing across partner units to match your target hand-feel.

Ask about finishing or request free swatches.