Rating methodology

What the ratings are

We rate each material on seven properties on a five-point relative scale. The value expresses how the material typically behaves compared with the other materials in the index – in an ordinary woven textile product for the home or for clothing.

We compiled the ratings from publicly available descriptions of fibre properties (fibre structure, absorbency, elasticity, dry and wet strength) and from the generally accepted differences between them, which we describe, with sources, in our articles.

What the ratings are not

• They are not laboratory measurements. We have not tested samples or used any test standards.
• They are not ratings of products or brands. A particular duvet cover may be better or worse than its material type suggests.
• They are not absolute. A “5” does not mean perfection, only the highest tendency within this index.

The same material can behave very differently depending on the weave (percale versus sateen), the yarn (single versus plied, combed versus carded), the finish (pre-washing, softening, crease-resistant finishes) and the fabric weight. A dense polyester satin and an open linen muslin differ more than “polyester” and “linen” as such.

The scale

Each value is shown in three ways at once: by the number of filled segments, by a number (for example 4/5) and by a word (low, moderate, medium, high, very high). No information is conveyed by colour alone.

Criteria

Softness

1 = crisp, firmer; 5 = very soft to the touch.

Breathability

1 = traps heat and moisture; 5 = lets heat and moisture escape very well.

Warmth

1 = feels cool; 5 = holds warmth.

Drying speed

1 = dries slowly; 5 = dries quickly.

Durability

1 = more prone to wear; 5 = withstands plenty of washing and use.

Easy care

1 = needs gentle handling; 5 = ordinary washing, no fuss.

Tendency to crease

1 = hardly creases; 5 = creases a lot.

For Easy care, a higher value means less fuss. For Tendency to crease, a higher value means the fabric creases more – so “more” is not “better” here. The values should not be added up.

Same score, different names

Egyptian cotton and Pima/Supima have identical values because they are the same botanical species with comparable staple length. Organic cotton has the same values as regular cotton because the “organic” label describes how it is grown, not the properties of the fibre.

Changes

If we find a reason to change a rating – a new reliable source, for example – we will record the change on the Corrections page.