Material

Microfiber

What it is

Microfiber is polyester, extruded as filaments fine enough that the fabric behaves differently from ordinary polyester cloth. The word describes the fineness of the fiber, not the fiber itself, so a microfiber sheet is a polyester sheet with a specific manufacturing spec. Listings use the texture word far more often than they use the fiber word, and both are accurate.

How it is made

Polymer is melted and pushed through spinnerets into filaments, then knitted or woven. Most bedding microfiber is then brushed on one or both faces, which raises a nap and produces the soft, slightly furry hand people associate with the material. Brushing is a mechanical finish, and how aggressively it is done varies more between sellers than anything else about the fabric.

When it is wet

Polyester absorbs very little water into the fiber itself; water sits between the filaments instead. That means microfiber wets through fast, dries fast, and feels wet at the surface sooner than cotton does. In a dryer it finishes well ahead of anything cotton in the same load, which is the practical reason a lot of households own a set.

When it is hot

The fiber does not take moisture in, so anything you sweat stays on the surface between you and the fabric. The brushed nap adds a layer of trapped air. Both of those work against you if you sleep hot, and it is the most common complaint attached to the material. Sellers answer with the word cooling, which is not a specification and not a measurement.

After fifty washes

Microfiber pills, and it pills more visibly than cotton because the pills are polyester and they hold color. The brushed nap flattens where the body rests, so the sheet develops a shinier patch through the middle. On the good side, the color stays: polyester takes disperse dye and holds it, so a microfiber set that has gone bobbly is usually still the color it started as.