By Alexei, founder of Loon Cabinetry. Written from our shop in Minneapolis, MN.

Most people who call us about custom kitchen cabinets ask about the doors first. Color, style, the shape of the profile. Fair enough, the doors are what you look at every day. But if you want a kitchen that still feels solid in fifteen years, the more important question is what the box is made of.

The box, or carcass, is the part you mostly don’t see: the sides, bottom, back, and shelves that everything else hangs on. It carries the weight of your dishes, takes the abuse of a slammed drawer, and lives right next to your sink and dishwasher where moisture is a fact of life. Three materials show up in that box across the industry: particle board, MDF, and plywood. They are not interchangeable, and the gap between them is wider than the price tag makes it look. Here’s how I think about each one, and what we build with.

Particle board: cheap, flat, and easy to wreck

Particle board is made from wood chips and sawdust pressed together with resin. It’s the most common box material in stock and flat-pack cabinets, and the reason is simple: it’s cheap and it comes dead flat.

The trouble starts when you ask it to do real work. Screws don’t bite well in it, so hinges and drawer slides can loosen or pull free over time, especially on doors that get used hard. It’s heavy for how weak it is. And water is its enemy. Get a leak under the sink and particle board swells, crumbles, and never comes back. I’ve torn out plenty of ten-year-old big-box kitchens where the sink base had turned to oatmeal. That’s why we don’t build with it.

One more thing worth knowing. Particle board and other composite woods are bonded with resins that can release formaldehyde into your home. There are federal limits on how much, set by the EPA under its rules for composite wood products, and it’s a reasonable thing to ask about with cabinets you’ll be cooking next to every day.

MDF: smooth, heavy, and thirsty

Medium-density fiberboard, or MDF, is particle board’s denser, finer cousin. Instead of chips, it’s made from wood fibers pressed into a smooth, uniform panel with no grain. Mass-produced cabinet lines use it for painted doors because it’s cheap to machine and takes paint without showing grain.

The catch is how it behaves over time. It’s heavy, and its raw edges soak up moisture if they aren’t perfectly sealed, which is a real problem in a room with a sink and a dishwasher. Like particle board, it’s a composite held together with resins that can off-gas. So it isn’t part of how we build. When we say furniture-grade, MDF isn’t in the mix.

Plywood: what we build boxes from

Plywood is built from thin layers of wood veneer glued together with the grain turned ninety degrees at each layer. That cross-grain construction is what makes it strong in every direction and stable when humidity swings. It holds screws like solid wood, weighs less than the composites, and shrugs off the odd splash far better than particle board ever could.

We build our cabinet boxes from furniture-grade plywood for all of those reasons. It costs more, and I won’t pretend otherwise. But the box is the one part of your kitchen you should never have to think about again, and plywood is how you get there. If you want the longer version of how we put a box together, I wrote it up in how we build the most durable custom cabinets in Minneapolis.

So what goes into a Loon kitchen?

Our build is straightforward. Cabinet boxes are furniture-grade plywood. Drawers are solid wood, so they can be sanded and repaired instead of thrown out when life happens to them. Everything gets a professional-grade finish that stands up to steam, wiping, and the occasional splash, and runs on soft-close hardware so nothing slams. Particle board and MDF don’t go into a kitchen we build. That’s the whole idea behind custom kitchen cabinets in Minneapolis instead of a box off a shelf: better materials in the spots that decide how long your kitchen lasts.

Why this matters more in a Minnesota kitchen

Our winters are dry and our summers are humid, and your cabinets feel all of it. Materials that move a lot or soak up moisture have a harder life here than they would in a mild climate. Add a working kitchen with a sink, a dishwasher, and drawers full of heavy stoneware, and the weak spots in cheap construction show up fast.

Good materials also make a kitchen easier to live with. Sealed, stable plywood boxes and quality finishes handle daily use without complaint. If you want the practical side of keeping them that way, we put together a guide on how to maintain custom kitchen cabinets.

How to tell what you’re really being quoted

Material is easy to gloss over on an estimate, and that’s exactly where corners get cut. So ask, in plain words, what the boxes are made of. “Plywood” and “engineered wood” are not the same answer, and if someone says “engineered wood,” push a little: does that mean particle board or MDF? You can also just look at a sample. Plywood shows its layered edge, particle board looks like coarse pressed crumbs, and MDF is smooth and solid all the way through. Pick up a piece if you can, because plywood feels lighter and more rigid than the same-size chunk of particle board.

A price that looks too good to be true usually is, and the box is often where the savings came from. If you want a hand reading an estimate line by line, here’s how to get an accurate estimate for your custom cabinets.

The bottom line

Doors get the attention, but the box and the build are what you’re really paying for. Particle board and MDF are what keep mass-produced cabinets cheap, and they’re also why those cabinets sag, swell, and loosen years before they should. Furniture-grade plywood, solid wood drawers, and a professional finish cost more up front and outlast the trends. That’s the build we stand behind on every kitchen.

If you’re weighing a custom kitchen and want to see and feel the difference yourself, take a look at our recent projects, or request a quote and we’ll walk you through exactly what goes into your cabinets.