In 1964, L'Oréal created Kérastase for the hair salons of Paris. Kérastase says it invented luxury hair care, and you can still hear the salon in the names: its shampoos are called bains, French for baths. Three of its gloss products are in this edit, and they are a good example of how a salon service moved into the shower.

A hair gloss used to mean an appointment. It was a sheer treatment your colorist brushed on to seal the surface of the hair so it reflected more light. Now it comes in two forms you can use at home. The first is the in-shower kind, a rinse-off treatment you use after shampoo, like a richer conditioner. The second is the finishing kind, serums, oils and sprays you put on after styling.

The first grid is in-shower glosses, for color that has gone dull and hair that feels rough. The second is the finishing products, for the glassy, light-catching look right before you walk out the door.

Here is a test I like: look at your hair by a window, not under bathroom lights. Dull hair looks flat in daylight even when it seems fine indoors, and that is when a gloss makes the biggest difference. Shine is mostly about a smooth surface, so anything that seals and flattens the outside of the hair will help.

These are the rinse-off glosses. They go on in the shower, and most work like a conditioner that leaves more shine behind. Use one weekly, in place of your usual conditioner.

OUAI's Hair Gloss is the easy place to start. After shampooing, split your hair into sections and work in a pea-sized amount. It has rice water and hyaluronic acid to boost shine, protect color and cut frizz. Oribe's Mirror Rinse is the richer choice, intensely hydrating for a silky, glassy finish.

For color care, Kérastase's Chroma Absolu gloss is a rinse-out salon gloss with lactic acid that seals the hair surface and helps preserve color. IGK's Hi-Shine Gloss Treatment, with amla oil and sea kelp, is also made for color-treated hair that has gone dull, and helps prevent fading. Moroccanoil's High Shine Gloss Mask is inspired by professional gloss services and adds intense conditioning along with the shine.

If you are short on time, Drybar's Liquid Glass Instant Glossing Rinse works in as little as ten seconds. Living Proof's PhD gloss is silicone-free and, in the brand's lab testing, doubled shine compared with untreated hair.

The odd one out is dae's Stargloss, which goes on before you shampoo. It has prickly pear and moringa oils and shea butter, so it smooths and hydrates while it adds shine, a good pick for hair that is dry as well as dull.

What I would skip: piling on extra product. A pea-sized amount per section is plenty, and more just weighs hair down.

The finish is where the glassy look really comes from. Everything here goes on the mid-lengths and ends, never the roots, so hair stays light.

Kérastase's Gloss Absolu line covers every stage. The All In One spray is a lightweight smoothing spray that detangles, fights humidity and protects from heat up to 450°F. Then choose by hair type: the Glaze Styling Cream is for medium to thick hair, silicone-free and made to keep a blowout smooth for up to four days, even in humidity. The Glaze Drops are the lighter version for fine and medium hair, a high-gloss oil with the same four days of frizz control.

Drybar makes two. The Miracle Smoothing Sealant is a heat-activated spray that the brand says lasts through three washes. The Liquid Glass serum is a finishing serum with nine types of hyaluronic acid that hydrates without weight and adds shine.

For a final mist, Chris McMillan's Glassy Smooth oil-mist is water-light, with heat protection up to 450°F, and Olaplex's No. 7 Shine Serum is a two-phase mist that combines a weightless oil with a repair treatment. IGK's Disco Disco is a clear shine spray with no greasy residue and some UV protection, the last thing I would do before leaving the house.

Here is a tip I like: spray the mist into your palms or onto a brush, not straight onto your head, so it lands where you want it.

What I would skip: layering every product in this grid. One smoother and one finishing product is plenty.

I think hair gloss is the most underrated step in hair care, because it does something you can see the same day. It will not change your hair overnight, but it makes whatever you have look cared for.

My routine is simple: an in-shower gloss once a week, then a few drops of serum or a quick mist on the days in between. Keep it on the lengths, check in daylight and stop when your ends catch the light. That is usually enough.