There is no best sheet fabric, only fabrics that suit particular people, climates and laundry habits. Someone who sweats through the night in a top-floor flat needs something different from a person who is permanently cold in a draughty cottage. Here is how the four common options behave once they are on a bed rather than in a photograph.
Cotton percale: the dependable default
Percale is crisp, matt and cool to first touch, and it improves for a few dozen washes before settling. It tolerates hot washing and rough handling better than anything else on this list. The trade-off is creasing, which is severe straight out of a machine.
Cotton sateen: sheen with a shorter life
Sateen floats threads across the surface for lustre and slip. It feels warmer than percale and snags more easily, because those floating threads are exposed. People who like a smooth, slightly heavy hand tend to prefer it.
Viscose from bamboo: slippery and moisture-hungry
Regenerated cellulose from bamboo drapes heavily, feels cool and moves perspiration quickly. It is weaker when wet, so it needs warm rather than hot washes and a low drying setting. Sets that state weight and pocket depth plainly, such as those listed on https://hotelsheetsdirect.org/, are easier to judge than ones sold on adjectives alone.
Linen: rough at first, excellent later
Flax has thick, irregular fibres that feel scratchy for the first month and then soften permanently. It handles humidity better than any other bedding fibre and lasts for decades with basic care. It also creases constantly, which some people find charming and others cannot live with.
Microfibre: cheap, warm, and honest about it
Finely spun polyester is inexpensive, resists creasing and survives student laundry. It does not absorb moisture, so a warm sleeper wakes up damp rather than dry. For a spare bed used twice a year it is a perfectly rational purchase.
Choosing by the problem you actually have
Start from the complaint rather than the fibre and the choice narrows quickly.
- Overheating at night: percale or viscose, lighter weight
- Cold bedroom in winter: sateen, flannel or brushed cotton
- Humid summers: linen above everything else
- Frequent hot washing for hygiene: cotton, nothing else
- Occasional guest bed on a budget: microfibre
Laundry habits should decide as much as feel
If you tumble dry on high and use softener out of habit, delicate fibres will disappoint you within a year. Cotton forgives that treatment, viscose does not. Be honest about how you launder before spending on something demanding.
Mixing fibres across the bed is allowed
Nothing requires the fitted sheet, flat sheet and pillowcases to match in fibre. A linen flat sheet over a viscose fitted sheet works well for people who want airflow above and slip below. Match the colour if it bothers you, but the fibres can differ.