What kitchen (and closet) cabinets are actually made of

The short version: almost every kitchen and closet cabinet has a box made of ¾″ (18 mm) melamine-faced chipboard (MFC)— it's stable, cheap and comes out of the press already finished, which is why it's the industry standard. The same board makes the shelves, partitions and drawer boxes. Doors and drawer fronts are usually ¾″ (18 mm) MDF for a painted finish; the back and drawer bottoms are a thin 5/32″ (4 mm) HDF. Plywood is the upgrade where a part carries real weight, and solid wood belongs to frames and edges, not the box. The trick is matching each board to its job.

The box and the doors are two different questions

Before any material talk, split the cabinet in two. The box (the carcass — sides, top, bottom, back, shelves) is structure: it has to stay square, hold shelves and take screws. The fronts(doors and drawer faces) are what you see and touch. They're chosen separately and they're usually different boards. In our own builds the box is MFC and the paint-grade fronts are MDF— both ¾″ (18 mm), but doing different jobs. So “what's it made of?” has more than one answer. Fronts get their own material story in door styles.

How each board is made, and what's inside

Every one of these boards starts as wood and ends as a flat sheet. What changes is how finely the wood is broken down and how it's bonded back together— and that's exactly what decides how each behaves in a cabinet.

• Chipboard / MFC. Wood is chipped into coarse particles, blended with resin, and hot-pressed into a flat panel — bigger chips in the core, finer ones near the faces. A decorative melamine-impregnated paperis then fused to both faces under heat and pressure, which is the wipe-clean colour surface you see. The particles and the resin are the whole board — and the cut edge is raw until it's banded, which is why water gets in there and nowhere else.
• MDF. Here the wood is broken all the way down to individual fibres, mixed with resin and wax, formed into a thick mat and hot-pressed into a dense, even panel. Because it's fibre rather than chips, there's no grain and no voids — one uniform body, which is why it machines to a crisp edge and paints flawlessly.
• HDF. Made like MDF but pressed harder and denserinto a thin, hard sheet (hardboard). That density is why a 5/32″ (4 mm) HDF back is stiff enough to square the box despite being so thin.
• Plywood. Thin veneersare peeled from a log and stacked with each layer's grain turned 90° to its neighbour, then glued and hot-pressed. That cross-grain stack — always an odd number of plies — is what makes plywood strong and stable in every direction at once.
• Solid wood. Simply sawn from a log and dried to a working moisture level. Nothing binds it back together, so it keeps moving with the seasons — the reason it stays out of the box and lives in narrow frames instead.

The short lesson: chips, fibres, veneers or planks. Finer and better-bonded means more uniform and stable (MFC, MDF); crossed layers mean strong and stiff (plywood); nothing bonded means it moves (solid wood).

Where each board goes, and how thick

A cabinet isn't one material — it's the right board in each spot. Here's exactly what we cut each part from, and the thickness we build in. Boards are stocked in a range of thicknesses; these are the ones that do the job without wasting money or weight.

MFC — melamine-faced chipboard (the standard box)

MFC is chipboard — wood particles pressed with resin into a flat sheet — with a tough melamine layer bonded to both faces. That skin is the finished surface: colour-matched, wipe- clean, no painting needed. Our board is ¾″ (18 mm) Egger White, and it does the most jobs in the cabinet. Its strengths are why it's the industry standard: dimensionally stable (a big flat panel stays flat), cheap and consistent, and finished in the press — no primer or lacquer on the inside of the box.

Where it's used, and how it does there:

• Sides, top, bottom & partitions. Its home turf — flat, stable, faced, cheap. The only real catch is water on a bare edge: an unbanded ¾″ edge wicks moisture and swells permanently, so every cut edge is taped.
• Shelves. Fine for normal spans, but ¾″ MFC sags first of the three boards — a long shelf under books or crockery will bow over time. Keep the span short, add a support, or step that shelf up to plywood.
• Drawer sides & backs.We build the drawer box from the same ¾″ MFC: sturdy, finished inside, and cheap. The trade is weight — it's a heavier drawer than a thin plywood or steel-sided one.
• Screw hold. Good in the face, weaker in the crumbly edge, and it dislikes being re-driven in the same hole — which is why our panels join with face-drilled connectors rather than screws into the edge.

Standard or moisture-resistant. You can have the carcass board two ways: standard MFC, or a moisture-resistant grade (usually a green-tinted core) made with a water-repellent resin. Worth being clear about what that means: it has a better moisture coefficient — it swells less and slower when it gets damp — but it is not waterproof and nothing like plastic. A soaked or unbanded edge will still fail in the end; the moisture-resistant board just buys margin in a splash-prone spot like under a sink or beside a dishwasher. It's a sensible upgrade there, not a licence to skip the edge banding.

MDF — the painter's board

MDFis wood fibre (finer than chipboard's chips) pressed into a dense, completely uniformsheet with no voids and no grain. It's stocked in a wide range of thicknesses — ¼″ to 1″ (6–25 mm) — and we use ¾″ (18 mm) where it belongs.

• Doors & drawer fronts (its real job). The uniform body mills to a crisp profile and paintsto a flawless, grain-free finish — the reason it's the king of facades. The cons live here too: a ¾″ MDF door is heavy (more load on the hinges), it can dent on a hard knock, and a raw edge is thirsty — a painted or foiled front seals it.
• In the box. Mostly not needed. It's heavier and pricier than chipboard with little structural gain for a plain flat panel, so MFC does the carcass for less. MDF earns a box spot only where a part is shaped or painted rather than laminated.

Plywood — the upgrade board

Plywoodis thin veneers glued in a stack with each layer's grain crossed against the next. That cross-banding is where its strength comes from. We stock a ¾″ (18 mm) birch plywood (Baltic-style, from Riga) as the premium, load-bearing option — and thinner ½″ and ¼″ (12 & 6 mm) for lighter parts. So — are plywood cabinets worth it? It depends on the part:

• As the box. Best screw hold (the crossed plies bite hard, face or edge), lighterfor the same panel, and the prestige of an all-plywood carcass. You pay for it: it's the priciest board, in a smaller sheet(about 60 × 60″ / 1525 × 1525 mm) so more offcut, cheap ply hides voids, and the face usually wants veneer or paint.
• As a shelf. This is where the upgrade pays off most: plywood is the stiffestboard, so a long shelf holds a line under load where ¾″ MFC would bow.
• As a drawer box.A ¾″ or ½″ plywood drawer is stronger and lighter than the MFC default — a genuine premium feel for a heavy kitchen drawer.

So MFC vs plywoodisn't “cheap vs good.” It's a stable, finished, inexpensive board against a stronger, lighter, pricier one. For most parts MFC is genuinely enough; plywood is the answer exactly where weight and span demand it.

HDF — the thin one (back panels & drawer bottoms)

HDFis chipboard's denser cousin — hardboard, wood fibre pressed flat and hard. We use it at 5/32″ (4 mm) for the two non-structural panels: the cabinet back and the drawer bottoms. Both sit captured in a groove and carry no load — they only keep the box square and close it against dust — so thin is correct, not a corner cut. It's cheap, dead flat and hard- wearing; the one rule is don't hang weight on it, because it isn't structural. A thick back would only add cost and weight for nothing.

Solid wood — where it's real, and where it's a myth

“Solid wood cabinets” sells, but it's mostly a misunderstanding. A wide panel of solid timber moves — it cups and cracks as humidity swings, which is precisely what a cabinet side must notdo. That's why the engineered boards above exist: they hold their shape where solid wood won't. Real solid wood earns its keep in the parts that are narrow and can move safely, in whatever thickness the design needs: face-frame rails and stiles, a shaker door'sframe, decorative edges. When an advert says “solid wood cabinets,” it almost always means solid-wood fronts on an engineered-board box— not a carcass carved from planks. We don't build solid-wood boxes, and neither should anyone.

The surface: what the front is finished in

The board is the core; the finishis the skin on top, and it's a separate choice — mostly on the doors and drawer fronts, where most of the look (and the cost) lives. On our fronts you can have:

• Melamine (MFC). The colour is baked into the board, factory-finished and cheapest — the default, and the same surface that lines the box.
• Paint on MDF. Any colour and sheen; the classic shaker or flat painted-kitchen look.
• Plastic (acrylic / laminate). A tough plastic skin pressed onto the board for a seamless high-gloss or super-matt front. Scratch- and moisture-tolerant, and common on modern handleless kitchens.
• Wood veneer. A thin skin of real woodbonded to the board — genuine timber grain without solid wood's movement. It's an expensive finishing operation, and it's how you get an authentic wood look on a stable, engineered core.
• Stone veneer. The exclusive, niche option — a paper-thin layer of real stone on a flexible backing, for a stone-look front that a solid slab could never hang as. Specialist and pricey, but genuinely stone.

Which finish suits which door — and the door shapes themselves — is the door styles story. The point here is that the core and the surface are two decisions: a stable board underneath, and the finish you actually see on top.

The edge, whatever the board

One choice sits on top of all of them. A cut edge of chipboard or MDF is raw, thirsty core; a strip of edge tape— our default is ABS, with PVC, melamine and veneer as options — laminates over it and seals it. Many shops skip banding hidden edges to save a pass on the machine; near water, don't. It's the same reason the bottom edge at the floor matters so much — and it applies to every board here, plywood included. The full story — thin vs thick tape, matched vs contrasting colour, and when a front is left un-banded on purpose — is in edge banding.

Durability, warping, and making it last

A board decides two different kinds of longevity: whether it holds its shape, and whether it survives water and wear. They're worth separating, because the answers aren't the same.

Warping and cupping. This is the good news about engineered board. MFC, MDF, HDF and plywood are all built specifically notto warp — chips, fibres and crossed veneers cancel out the movement that makes a solid-timber panel cup and crack with the seasons. The shape-change to actually watch for isn't twist, it's sag: a long, heavily loaded ¾″ (18 mm) MFC or MDF shelf slowly bows under sustained weight. A mid-support or a step up to plywood fixes it. Solid wood is the outlier that genuinely warps and cups with humidity — the whole reason it never becomes a wide box panel.

Water, wear and how long it lasts. Kept dry and edge-banded, an engineered-board box lasts decades — this is the standard material in millions of kitchens, not a compromise. The failure mode is almost always the same one: water reaching a bare, unbanded edge, where the core swells permanently and can't be undone. So real-world durability is less about which board you pick and more about whether the edges are sealed and the box is kept up off wet floors.

Treatment and finishing. Protecting an engineered board means finishing its faces and its edges. MFC arrives face-finished (the melamine skin); its cut edges are sealed with edge tape — ABS, PVC, melamine or veneer. MDF and plywood need paint, foil or veneer on the faces plus banding on the edges. For the wettest spots — under a sink, next to a dishwasher — moisture-resistant grades of chipboard and MDF exist; whether a given project needs one is worth asking us about.

So which should you pick?

• MFC (melamine chipboard), ¾″ (18 mm) — the right default for the box, shelves, partitions and drawer boxes: stable, finished, affordable, and completely enough for a normal kitchen as long as the edges are banded.
• Plywood, ¾″ (18 mm)— the upgrade where it earns it: long shelves that mustn't bow, heavy doors and pulls, or an all-plywood box you'll pay for.
• MDF, ¾″ (18 mm) — the board for doors and drawer fronts and painted parts, not the plain carcass.
• HDF, 5/32″ (4 mm) — the back panel and drawer bottoms, thin because they carry no load.
• Solid wood — for face frames, shaker frames and edges, never the box panels.

The quick version, by situation

• Standard kitchen, sensible budget, or a rental— MFC throughout. It's what most of the market ships, and it's completely fine kept dry and banded.
• Long open shelves or a loaded pantry — plywood shelves, so they hold a line instead of bowing.
• Heavy drawers (a stone-top kitchen, big pans) — plywood drawer boxes for strength with less weight.
• Painted or shaker fronts — MDF doors and drawer fronts; the box underneath stays MFC.
• Wet spots(under the sink, by the dishwasher) — the board matters less than keeping the box off the floor and banding every edge; ask us about a moisture-resistant grade if it's a real soaker.

You don't have to settle this on a spec sheet. Build the cabinet in the editor, and every part — box, shelves, back and edges — is priced to the millimetre, so you can see what the material choice costs on your design and weigh it against what cabinets cost overall.

Why it pays to ask what it's made of

Two cabinets can look identical in a showroom and be built completely differently. “Chipboard” or “MDF” isn't a single thing — the same name covers boards from different manufacturers that vary a lot in density, surface toughness, how flat they stay and the quality of the resin holding them together. A budget board and a premium one can wear the same label. So when you compare quotes, ask the plain question: which board, and whose.

The material is one of the biggest levers on a cabinet after its size — it moves cost, durability and price together. Three things drive that, and only one of them is visible on a spec sheet:

• Which board, and which maker. A denser, better-faced board costs more and lasts longer; a cheap one saves money now and shows it later. Same name, different cabinet.
• How much material is used. Price tracks the board that goes in — a full-thickness back instead of a thin one, more shelves, deeper boxes all add material, cost and, usually, sturdiness. Less board is cheaper, and sometimes flimsier.
• Whether the process is respected. The classic corner to cut is edge banding: sealing every cut edge of MFC is what keeps moisture out of the core, so skipping it on hidden edges is cheaper to build and quicker to fail. A suspiciously low quote has often saved exactly here.

On our side, the board and the banding are only part of it — we also detail the constructionso parts don't sit against wet zones where we can avoid it: the box kept up off the floor on legs or a plinth, edges sealed where water lives, joints kept out of the splash. The board matters; so does how it's put together around the water.