The complete guide to nail polish

Nail polish is one of the oldest products in the beauty cabinet and one of the least explained. Most people learn it by trial: too many coats, a smudge at the door, a chip on day two. The chemistry behind it is short, and once you know it, most of the trial goes away.

A manicure has a whole life: what the liquid in the bottle is, which finishes exist, how to choose a colour that suits your skin, how many coats to apply, why polish chips, how to take it off, and how regular lacquer compares with gel.

What is nail polish and how does it dry?

Nail polish is a lacquer that forms a thin, hard film on the nail once its solvents evaporate. The film-former in a classic polish is nitrocellulose. It is dissolved in volatile solvents, mainly butyl acetate and ethyl acetate, together with resins for adhesion and gloss, plasticisers for flexibility, pigments for colour and clay-type agents that keep the pigment suspended, according to Personal Care Magazine.

Solvent polish dries from the bottom up. The solvents leave the film, the nitrocellulose and resins lock together, and the coat hardens. A regular polish is touch-dry in about 3 to 5 minutes and knock-resistant soon after, but it takes several hours to harden all the way through, per Nagelstudios.nl. Quick-dry formulas set the surface in 30 seconds to 2 minutes.

Thin coats dry faster and harder than thick ones, because the solvent has less distance to travel out. A UV or LED lamp does nothing for regular polish, because there is no photoinitiator in the bottle to react to it.

Which finishes exist and how do they differ?

A finish is the way a polish handles light once it is dry. The pigment load, the particle type and the top coat decide it. Crème, jelly, shimmer and pearl are the base finishes. Metallic, magnetic, thermal, multichrome and glitter are the effect finishes.

Shimmer particles hide ridges better than a crème, so a shimmer is the forgiving choice for uneven nails. Magnetic polish works in gel and in air-dry lacquer; in an air-dry formula the magnet must be set within seconds, before the film levels. Nebula by India Anaïs is one example of a lamp-free cat-eye; it is sold out, and the next edition is planned for spring 2027.

How do you choose a colour that suits your skin?

Undertone is the warm, cool or neutral cast beneath the surface of the skin, and it does not change with a tan. Two quick tests find it. Look at the veins on the inner wrist: blue or purple veins point to cool, green to warm, a mix to neutral. Then hold silver and gold jewellery against the hand and see which one makes the skin look clearer, per L'Oréal Paris.

Red is the shade where undertone shows first. Cool undertones suit blue-based reds such as cherry and raspberry. Warm undertones suit orange-based reds such as tomato and brick. Neutral undertones can wear a true red. Celebrity manicurist Deborah Lippmann gives the same rule in Who What Wear, with one caveat: the rule is a starting point, not a limit.

Nude is the shade where depth matters most. A nude that matches the skin exactly makes the hand look like a mannequin. The fix is a nude that is one step lighter or darker than the skin, or one that moves in a slightly different undertone direction. Beige is not a nude on deep skin; caramel, cognac, chocolate and berry-browns are. Olive skin, which shifts between warm and cool with the light, does best in dusty rose or mauve-nude, because yellow-based nudes turn grey on it.

Beyond red and nude, six shades work in every wardrobe: a sheer nude, a milky white, a true red, an oxblood, a black and a deep violet. Pale, olive and deep skin each have colour families that flatter them. Short nails have their own rules: mid-tone and sheer shades, a tapered shape and a very thin French line all make a short nail read longer.

Sheer or opaque, and how many coats?

Coverage is the amount of the nail a polish hides. An opaque polish, usually a crème, hides the nail in two coats. A sheer polish, usually a jelly, tints the nail and builds with each coat. Sheers forgive mistakes and suit short nails; opaques give the flat, saturated look of a classic red or a black.

The standard count is four coats in total: one base coat, two thin colour coats and one top coat. Two thin coats beat one thick one because a thick coat traps solvent, stays soft underneath and dents or peels. The exceptions are sheers, which may take three thin coats to reach the depth you want, glitter toppers, which often need one, and magnetic polish, which is set with the magnet after the second colour coat.

Between coats, wait 1 to 2 minutes so the surface sets before the next brush touches it, following Manucurist.

What do a base coat and a top coat do?

A base coat is a clear, slightly sticky film that goes on the bare nail before colour. It does three jobs. It gives the colour something to grip, so the manicure wears longer. It blocks pigment from soaking into the nail plate, which is why reds, blues and dark shades stain nails that were painted without one. And a ridge-filling base, which contains silica or talc, smooths fine grooves before colour goes on.

A top coat is a hard, clear, high-gloss film that goes over the dried colour. It protects against abrasion and gives the shine. Quick-dry top coats use a higher solvent load and faster solvents to set in 1 to 2 minutes. Matte top coats add silica to scatter light. Gel-effect top coats are thicker, high-solids films that build a domed, glass-like shine and are the base of the glass-nail look, per Essie and Manucurist.

Reapply top coat every 2 to 3 days. The top coat wears before the colour does, so this one habit adds the most days to a manicure.

How do you apply nail polish so it lasts?

Most chips are decided before the colour goes on. Oil, cuticle skin and water on the nail plate all stop the film from bonding. Skip the water soak: a soaked plate swells, then shrinks under the polish and cracks it.

You will need

• Nail polish remover and lint-free pads
• A file and a fine buffer (240 grit or finer)
• Cuticle softener and a steel or plastic pusher
• Base coat, colour and top coat
• A small flat brush and remover for clean-up
• Cuticle oil for afterwards

Steps

1. Remove old polish. Apply cuticle softener, wait, then push the cuticle back gently. Nip only hangnails.
2. File to shape in one direction. Buff the surface lightly with the fine side of the buffer.
3. Wash the hands, dry them, then wipe each nail with remover or alcohol to degrease. Scrub the corners of the nail plate; this is where lifting starts.
4. Apply one thin base coat.
5. Apply the first colour coat in three strokes: one down the centre, one down each side. Wipe the brush on the neck of the bottle first so it picks up a small bead, not a blob. Cap the free edge by running the brush along the tip.
6. Wait 1 to 2 minutes. Apply the second thin colour coat the same way.
7. Apply top coat, again capping the free edge. Clean the edges with the small brush dipped in remover.
8. Keep hands still for 10 minutes. Add a drop of cuticle oil once the surface is dry.

Bubbles come from shaking the bottle, from painting in heat or from a coat applied over one that was still wet. Roll the bottle between the palms instead of shaking it. A smudge in the first few minutes can be smoothed by pressing a fingertip wetted with remover over it, then adding a thin coat of colour and top coat.

How long does nail polish last and why does it chip?

Regular polish wears 3 to 7 days on fingers, depending on preparation and top coat. In a side-by-side test by Who What Wear, Chanel Le Vernis reached about one week without chips. Toenails grow at about half the speed of fingernails and take less impact, so the same polish lasts far longer on toes.

Polish fails at three points, per Manucurist. Before painting: dehydrated or weak keratin, and a plate that was not degreased. During painting: thick coats, no base or top coat, too little dry time between coats. After painting: hot water, which swells the plate and loosens the film, household chemicals, and impact from typing or opening cans.

Wear gloves for washing up and cleaning. Avoid long hot baths in the first day. Refresh the top coat every 2 to 3 days and oil the cuticles daily, so the plate stays flexible and bends with the film.

How do you remove nail polish without damage?

Acetone is the fastest solvent for polish and the one salons use. It is not toxic, but it dries out the nail plate, the cuticle and the surrounding skin, so keep contact short and moisturise afterwards. Dermatologists at Sinclair Dermatology describe acetone as the most effective and least traumatic way to take off varnish, because the alternatives need more rubbing.

Acetone-free removers are based on ethyl acetate or isopropyl alcohol. They are gentler on skin and slower on polish, and they struggle with dark crèmes, glitter and magnetic pigment. For those, hold a soaked pad on the nail for 10 to 20 seconds, then wipe from cuticle to tip in one pull. Dense glitter comes off cleanly with the foil method: a soaked pad on each nail, wrapped in foil, left for a few minutes.

Do not scrape or peel. Peeling takes the top cells of the nail plate with it and leaves white patches that take months to grow out.

Regular polish or gel, and luxury or drugstore?

Gel polish is a lacquer of acrylate monomers and a photoinitiator that hardens under a UV or LED lamp. It wears 2 to 3 weeks on fingers and 6 to 8 weeks on toes, with no dry time and a high gloss, per Etos. The costs are removal, which needs filing and a 10 to 15 minute acetone soak, the risk of acrylate allergy, and repeated UVA exposure. Cleveland Clinic dermatologists note that no nail lamp is risk-free and suggest keeping gel to a few times a year, per Cleveland Clinic.

Regulation also separates the two. The photoinitiator TPO has been prohibited in cosmetics across the EU since 1 September 2025, and the monomer HEMA is restricted to professional use, per Cosmetics Business. Both rules concern gel only. Air-dry lacquer contains neither.

On price, prestige polish costs roughly three to five times more per millilitre than a drugstore bottle. Hermès Les Mains is 15 ml, Chanel Le Vernis 13 ml and Dior Vernis 10 ml, at around $34 to $66 in the United States, against about $10 to $12 for Essie and OPI, per Who What Wear and the brands' own sites. The money buys pigment concentration, a heavier bottle and brush, and skincare-style additives such as Chanel's camellia ceramides. It does not buy a different chemistry, and wear tests put the two tiers within days of each other.

How do you store nail polish, and can it fly?

Polish thickens when solvent escapes. Keep the cap tight, wipe the neck of the bottle before closing, and store the bottle upright in a cool, dark place. Heat and sunlight are the two things that shorten its life; a fridge is not needed.

A thickened polish is revived with a few drops of nail polish thinner, which is solvent, and never with remover, which contains oils and water that ruin the film. When a polish separates and stirring or thinning no longer brings it back, or when it smells sour, it is finished.

A 10 to 15 ml bottle is well under the hand-luggage limit for liquids, so it can fly in the clear bag with other toiletries. Polish is flammable, so it belongs in the cabin bag under the liquid rules and never loose in a hot car.