Combed, Carded, Sanforized: Spec-Sheet Terms Explained

Carded and combed yarn

Before staple fibres can be spun into yarn they have to be cleaned and aligned. Carding does the first pass, opening the fibre mass and laying the fibres roughly parallel. A yarn spun straight after carding is a carded yarn, and it still contains the full range of fibre lengths, including short ones.

Combing is an extra step after carding that removes the shortest fibres and aligns the rest more precisely. A combed yarn is therefore made from longer, more parallel fibres. Removing material costs money twice, once in the processing and once in the fibre discarded, which is why combed yarn always carries a higher price than carded yarn of the same count.

What the difference means in a uniform

The protruding fibre ends on a carded yarn are what a wearer eventually notices. They give a slightly warmer, less smooth handle, and under abrasion they are what forms pills on the fabric surface. A combed yarn, with those short fibres already removed, stays smoother through more wash and wear cycles.

That does not make carded yarn the wrong choice. For a high-volume program where cost per metre governs and the garment will be replaced on a cycle, carded yarn is often the sensible specification. Where the fabric is close to the skin, or the garment is expected to look presentable for years, combed is usually worth the difference. The decision belongs to the program, not to a general rule about quality.

Sanforizing and residual shrinkage

Cotton-containing fabric shrinks when it is first washed, because weaving and finishing leave the yarns held under tension that the first wash releases. Sanforizing is a controlled mechanical pre-shrinking process: the fabric is compressed and shrunk under steam before it ever reaches a buyer, so that most of the shrinkage that would have happened in the first wash has already happened at the mill.

A sanforized fabric is not a fabric that cannot shrink. It is a fabric whose remaining shrinkage has been brought within a stated limit, usually expressed as a residual shrinkage percentage. That figure is the number worth asking about, because sanforized on its own is a description of a process rather than a guarantee of a value. Our shrinkage guide covers how residual shrinkage is tested and what to specify.

Why poly-viscose fabrics are heat-set, not sanforized

Polyester is a thermoplastic fibre, which means its shape can be fixed with heat. Poly-viscose and poly-cotton fabrics are therefore stabilised by heat-setting, passing the fabric through controlled heat so the polyester component is locked into a stable dimension. It is the equivalent step to sanforizing, achieved by an entirely different mechanism.

This is why asking for a sanforized poly-viscose suiting is a specification error rather than a demanding requirement. The correct question for a polyester-rich blend is what the dimensional stability is after a stated wash, and whether the fabric has been heat-set. Most of our range is poly-viscose, poly-cotton and polyester, so heat-setting rather than sanforizing is the relevant process across the catalogue.

Mercerised, and other cotton-only terms

A few other spec-sheet terms apply only where cotton is present, and they get quoted loosely on blends where they mean nothing. Mercerising treats cotton with a caustic solution under tension, which increases lustre, strength and dye uptake. It is a genuine and visible improvement on a cotton fabric, and it has no meaning on a fabric with no cotton in it.

The general point is worth carrying into every specification you read. Process terms belong to fibres. A term borrowed from cotton finishing and applied to a polyester blend is a sign the specification was assembled rather than written, and it is worth querying before it becomes a contractual requirement nobody can actually test.

What belongs on your specification

Rather than requesting process names, specify the outcome you need and let the mill state the process that achieves it. Outcomes are testable; process names are not always relevant to the blend in question.

• The blend and its ratio, since that determines which processes even apply
• Yarn count, and combed or carded where the handle and pilling behaviour matter to you
• Dimensional stability as a permitted shrinkage percentage after a stated wash
• Whether the fabric is heat-set, for polyester-rich blends, or sanforized, where cotton is present
• Pilling resistance, where the garment will see heavy abrasion

Our guide to reading a fabric spec sheet covers how these fields sit alongside GSM, width and weave, and the yarn counts guide explains how count is written and what it implies.

FAQ

Frequently asked questions

Is combed yarn always better than carded?

It is smoother, stronger for the same count and less prone to pilling, and it costs more. Whether that is better depends on the program. For high-volume uniforms on a replacement cycle, carded yarn is often the right economic choice; for garments worn close to the skin or expected to look presentable for years, combed usually earns its cost.

Can a poly-viscose fabric be sanforized?

Sanforizing is a pre-shrinking process for cotton-containing fabric. A polyester-rich blend is stabilised by heat-setting instead, which fixes the polyester component's dimensions with controlled heat. For a poly-viscose suiting, ask about heat-setting and about dimensional stability after a stated wash rather than about sanforizing.

Does sanforized mean the fabric will not shrink at all?

No. It means most of the first-wash shrinkage has already been taken out at the mill and the remainder has been brought within a stated limit. The useful figure is that residual shrinkage percentage, not the word itself.

Why does carded fabric pill more?

Because the short fibres that combing removes are still present, and their ends protrude from the yarn surface. Under abrasion those ends tangle into small balls on the fabric face. Removing them at the combing stage is what makes a combed yarn stay smoother for longer.

Does mercerising apply to uniform suitings?

Only where cotton is present, since it is a treatment of cotton fibre. On a poly-viscose or all-polyester suiting the term has no meaning, and seeing it in a specification for such a fabric is usually a sign the specification needs querying.