How to wash straight hair: the routine that keeps roots up

Straight hair has one structural advantage and one structural problem, and they are the same fact: there is nothing in the fibre's shape to slow sebum down. Oil produced at the scalp travels the length of a straight strand easily, which keeps the ends conditioned and the roots looking greasy by the second day.

Every decision in a straight-hair wash routine follows from that.

How often to wash straight hair

Every two to three days suits most people. Daily is fine — better than fine, if your scalp is oily or prone to flaking — and the guilt attached to daily washing is manufactured. The claim that washing less trains your scalp to produce less oil has been tested by measuring sebum output, and it does not hold up. What changes over a fortnight without washing is your reference point, not your glands.

The signal to watch is your scalp on the last day before a wash. Comfortable is right. Itchy, tight or visibly oily means the interval is too long.

The five steps

1. Rinse for thirty seconds first. Warm, not hot. Water alone loosens a surprising amount of sebum and product, and hair that is properly saturated needs far less shampoo — which matters, because most straight-hair problems are quantity problems.

2. Shampoo the scalp only. A coin-sized amount, emulsified between your palms with a little water, applied to the scalp in a few places. Work with fingertips in small circles: front hairline, crown, both sides, then behind the ears and the nape, which is where nearly everyone stops short. Thirty seconds of contact with the skin.

3. Let the run-off do the lengths. Do not scrub the mid-lengths and ends. They are the oldest hair on your head, they carry the least oil, and full-strength surfactant on them is how the greasy-roots-dry-ends combination gets built. The technique is the same for everyone; straight hair simply punishes getting it wrong faster.

4. Condition the last third only. A lightweight formula, applied to soaking-wet hair, from mid-length down. On fine straight hair, the last quarter. Two to three minutes is enough — most of the deposition happens in the first couple of minutes and waiting longer mainly wastes time.

5. Rinse thoroughly, then cooler. Straight hair shows residue immediately, so rinse for about twice as long as feels necessary. Finish cooler if you like the way it feels.

Where the volume actually comes from

Not from the shampoo. From the drying.

Hair sets into the shape it holds as the last water leaves it, so dry the root area first, flipping each section against the direction it naturally falls, and let the lengths finish afterwards. A cool shot at the end locks the shape as the hair cools. Ten minutes with velcro rollers on the crown while you do something else beats almost anything in a bottle.

If flatness is your main complaint rather than oiliness, the fine hair guide is the longer version of this paragraph — most of it is about weight rather than washing.

What to reach for

Generic types rather than brands, because the category matters and the bottle mostly does not:

• A gentle daily shampoo, or a volumising one, which is generally a shampoo that cleans a little more thoroughly and deposits a little less.
• A lightweight conditioner — anything described as rich, deep or intensive is for someone else's hair.
• A clarifying shampoo, kept for once every four to eight weeks or whenever the hair starts feeling coated. Straight fine hair shows buildup sooner than any other type.
• Dry shampoo, for day two, used sparingly. Layered across four consecutive days it becomes the buildup it was meant to postpone.

Straight hair and heat

Straight hair is the type most likely to be blow-dried daily and least likely to think of it as damage, because the result looks smooth. It accumulates in the fibre all the same. Medium heat at a distance, a protectant before the dryer, and the iron reserved for days when the dry alone did not do it — the temperature bands are worth knowing even if you never use a straightener above the middle setting.