There are two families of wood finish, and the difference between them decides how your furniture will look in ten years more than the species does.
Penetrating finishes soak into the wood and harden inside it. The surface you touch is wood.
Film finishes sit on top as a continuous layer. The surface you touch is plastic.
Everything else is detail.
The central trade-off
A film finish protects better. It resists water, alcohol and heat far more effectively, because liquid never reaches the wood.
A penetrating finish repairs better. Damage is local and can be fixed in place, in minutes, invisibly.
Film finishes fail in a way that cannot be patched. When a lacquer surface wears through in the middle of a table, the repaired patch will always show, because you are now looking through two different thicknesses of clear plastic. The only real fix is stripping the whole surface.
Oil finishes wear gradually and evenly, and every stage of that wear is fixable with a cloth and twenty minutes.
Hardwax oil
A blend of natural oils and waxes that penetrates and cures inside the timber while leaving a thin wax layer at the surface.
For: looks and feels like wood, not plastic. Repairable in place with no visible patch. Easy to apply and reapply. Ages gracefully. Matte to low sheen.
Against: less resistant to standing water and alcohol than a film. Needs reapplying, annually on a dining table, every few years on lower-use pieces. Will show a water ring if liquid sits for an hour.
Right for: almost all furniture where it will be touched and kept a long time. Especially good on anything with texture, carved pieces, live edge, anything where a plastic film would flatten the surface.
Tung and danish oil
Pure penetrating oils, the traditional option. Beautiful depth, extremely repairable, and the least protective of everything here. They need frequent reapplication and offer little defense against water.
Danish oil is usually a blend of oil and varnish, giving slightly more protection than pure tung at the cost of some of the feel.
Polyurethane
The most common film finish and the most protective in ordinary use. Water-based versions stay clear; oil-based versions add warmth and continue to amber over years.
For: excellent resistance to water, heat and solvents. Low maintenance. Available from satin to gloss.
Against: feels like plastic. Cannot be spot-repaired. When it eventually fails it must be stripped entirely. A thick gloss coat makes good timber look like a photograph of timber.
Right for: kitchen surfaces, bathroom vanities, floors, anything in a rental, anything that will be cleaned aggressively.
Lacquer
The furniture industry standard because it sprays fast and dries in minutes. That is a manufacturing advantage, not a user one.
Thinner and harder than polyurethane, so it shows detail better, but more brittle and less resistant to solvents, nail polish remover will go through lacquer quickly, which is worth knowing on a makeup vanity.
It can be spot-repaired by a professional, because fresh lacquer partially dissolves into the old, but this is a skilled job rather than a household one.
Varnish
The tough outdoor option. Marine and spar varnish stay flexible and contain UV absorbers, which is what outdoor timber actually needs.
Slow to apply, ambers noticeably, and generally too heavy for indoor furniture. Its place is outside.
Wax alone
Lovely feel, almost no protection. It is a top coat, not a finish. Wax over bare wood offers no defense against water at all.
Its legitimate use is over another finish, to add sheen and slip.
Epoxy coating
A thick pour of clear resin over the surface. Completely waterproof, very tough, and it changes the character entirely, the wood ends up under glass.
Used deliberately on river tables and bar tops. Not repairable, yellows over years under UV, and it traps any moisture still in the timber, which causes problems if the wood was not fully dry.
Which finish for which piece
- Dining table: hardwax oil if you will maintain it, polyurethane if you will not.
- Coffee table: hardwax oil. Marks are inevitable and repairability matters most.
- Desk: hardwax oil. Forearms on a plastic film is the wrong feel eight hours a day.
- Bathroom vanity: polyurethane or a marine-grade finish. This is the one place to choose protection over feel.
- Kitchen countertop: hardwax oil if food is prepared directly on it and it is maintained; polyurethane if it is a decorative surface.
- Shelving and wall pieces: hardwax oil. Little wear, and the texture matters.
- Outdoors: exterior oil or spar varnish, maintained annually. Nothing else survives.
How to tell what you already have
One drop of water on a hidden area, left two minutes.
Beads and wipes clean, film finish. Darkens and fades as it dries, penetrating. Soaks in and stays, unfinished or failed.
The care method follows from the answer; see how to clean wood furniture.
Which trade-off to accept
Furniture meant to be used for decades and repaired rather than replaced depends on damage being fixable by the owner, at home, without a specialist. A film finish works against that. The first deep scratch on a lacquered table is permanent unless the whole top is refinished. The first deep scratch on an oiled one is a sanding block and twenty minutes.
The trade runs both ways, and it is worth stating plainly. An oiled surface needs recoating from time to time, and it will mark if a wet glass sits on it overnight. A film finish asks nothing of you until the day it is damaged, and then it asks for a professional. Decide which of those two futures you would rather have, and check which finish a piece actually has before you buy it.