Ask a showroom whether the boxes are plywood and you get a yes or a no, and either way you have learned a fraction of what you wanted to know. A cabinet box is not one material. It is a bottom panel, two gables, a back, shelves, and on a framed cabinet a hardwood grid across the front. Those parts do different jobs. One sits under a plumbing trap for the life of the kitchen. One carries the hinge screws. One spans the widest opening in the run with tinned food standing on it.
"All-plywood construction" is the only cabinet specification most people are ever offered, which makes it the only one they can compare. So the panels that actually fail get chosen by default, in a factory, by whoever was buying sheet goods that week. The useful question is not plywood or particleboard. It is which panel, in which cabinet, and what arrives at it.
Three cores, and how each one breaks
These are not grades of the same product. They fail in ways that do not resemble each other.
Plywood
Thin veneers laid up with the grain of each ply crossing the one below, glued and pressed. The cross-banding is the whole trick: wood moves across the grain and barely along it, so alternating layers hold each other still. What comes out is stiff for its weight, holds a screw in its face and reasonably in its edge, and survives an event. Plywood that gets wet swells, then mostly dries back to itself.
What plywood is not is uniform. Cheaper panels carry voids in the inner plies, gaps where a core veneer ran short, and a void behind a hinge screw is a screw in air. Plywood is also less flat than a manufactured panel, which matters on a long run where door reveals have to stay even end to end.
Particleboard
Chips and resin pressed to density. The industrial furniture board a cabinet shop buys and the material in flat-pack shelving share a name and not much else, and the density between them varies enormously.
Its virtues are real. It is dead flat, it stays flat, and it takes a melamine or laminate surface better than plywood does, because there is no grain underneath waiting to read through.
Its failure mode is water, and the failure is not gradual. Water finds an unsealed edge, the chips swell, the resin bond releases, and the panel takes on the texture of oatmeal. It does not dry back. Plywood recovers from an event. Particleboard records it.
Screws are the other one. A screw in the edge of a chip core has glue and chips to bite instead of fiber running the right way. It holds until it is backed out once, and then it does not.
MDF
Fibers rather than chips, denser, the same all the way through. It machines to a clean profile with no grain to tear, which is why a routed door panel is usually MDF, and it paints better than any other wood product because there is no grain to raise and no seasonal movement to open a joint in the finish.
It is heavy, which changes how a tall cabinet hangs and how a wide door loads its hinges. It drinks water at a raw edge as fast as particleboard, and being denser it is worse at giving it back. MDF belongs where you want a painted surface that stays flat, not where you want a panel that shrugs off a leak.
The thing that is not a fourth material
Melamine, thermally fused laminate, prefinished maple veneer — those are surfaces bonded to one of the cores above, not cores themselves. When a quote says melamine boxes, the question is what the melamine is stuck to. Over particleboard and over plywood it looks identical under showroom lighting and behaves nothing alike under a weeping trap.
Where the water arrives
Every core here is fine until water finds an unsealed edge. Two cabinets in a kitchen get wet in ordinary use.
The sink base
If you upgrade one panel in a kitchen, upgrade this one.
The sink cabinet is the only box in the room with a trap, two supply stops, usually a disposal, often a filter, and on many layouts the dishwasher's discharge loop. Every one of those is a joint, and joints seep long before they fail. A weep from a compression stop wets a patch the size of a coin for weeks before anybody notices, because it lands behind the bin.
On plywood that is a stain and a repair to the stop. On a chip core it is a new cabinet floor and often a new cabinet, because the swelling is permanent and by the time it shows it has traveled into the bottom edge of the gables either side.
When we build or order boxes, the sink base gets specified apart from the run: a plywood floor, sealed edges where the panel is bored for the drain and the stops, and a liner over the top that lifts out. The liner is not there to stop water. It is there to hold water where you can see it.
Beside the dishwasher
A dishwasher vents steam at the end of its cycle, and plenty of machines vent low, straight at the gable beside them. Add a leak landing on the floor of the run and wicking into whatever raw edge it finds, and that panel is the second wettest in the kitchen without ever being splashed. Good place for plywood, or at minimum a properly banded edge on the face that looks at the appliance. The toe kick below is the lowest edge in the room and takes mop water, dropped ice and eventually the refrigerator line.
Where the load is
Shelves and the span
Shelf sag is mostly span, then thickness, then load, and only after all three is it material. Loaded across a wide cabinet, a particleboard shelf takes a set and keeps it. Plywood deflects less. Both deflect.
The fixes are identical either way. Shorten the span with a partition. Glue a hardwood strip to the front edge so the shelf works as a shallow beam. Or put the heavy things in drawers, which is the right answer more often than people expect and the argument running through storage that earns its money.
Where the hinge screws land
This is where core material stops being abstract, and it depends on how the cabinet is built. On a framed cabinet the hinge screws go into the solid hardwood face frame, and the gable behind it is mostly a wall. On a frameless cabinet the hinge plate mounts to the gable itself, so the side panel becomes structural hardware and the fastener in it starts to matter. Shops use a particular screw there, driven into a drilled and sized hole, because an ordinary wood screw in a chip core does not hold.
Which is why this reads better against what changes inside the cabinet than on its own. Frameless boxes in a low-density panel, hung with whatever screws came in the bag, is a kitchen whose doors need re-hanging.
The back, and how the run hangs
A wall cabinet full of plates hangs off its back panel and the fasteners through it. A thin hardboard back captured in a groove is a dust panel, not structure. The load has to reach a hanging rail, and the rail has to reach studs. Boxes that fail here fail visibly: the cabinet leans off the wall at the top, the doors go out of reveal, the joint at the crown opens. The panel is half of that. How it hangs is the other half.
Doors are a separate decision from boxes
The right box material and the right door material are frequently not the same, and that is not a contradiction. For a painted door, an MDF center panel beats solid wood. A solid panel shrinks in January and shows a thin unpainted witness line where it sat when it was sprayed. That is not a defect — it is what wood does in this climate — and paint does not hold a moving joint together. For a stained door you want solid wood and you take the movement as part of the look.
Thermofoil is MDF wrapped in a vinyl skin, and heat beats that bond eventually, which is why the first lifting corner is nearly always the door beside the oven. Where doors get sprayed rather than bought, the substrate decides more than the can does: a factory finish is prep, environment and cure time on a surface that holds still.
What this does to a quote
We do not publish our own numbers, for the reason we give everywhere else: a price written before anyone has seen your kitchen is a guess. What we can point at is independent research on this market. Angi, Homeyou and Block Renovation research puts an Indianapolis kitchen project at roughly $18,000–$24,000, with the full spread running about $8,000–$40,000.
Cabinets and stone are the bulk of any kitchen quote, which is why box specification moves the total so much, and why the gap between two quotes for the same room is so often invisible in the paperwork. Nobody itemizes a gable.
Worth saying plainly: upgrading an entire kitchen to plywood is not always the best use of that money. With dry runs, short shelf spans and framed construction, the difference on the far wall is close to academic, and the same money does more in drawers, in better slides, or in the panels that get wet. Spending it everywhere is easy to sell. Spending it where the water is takes a walkthrough first.
Questions worth asking
Take these to whoever is quoting you. The answers separate a specification from a sales line.
- What is each part made of — gables, bottoms, backs, shelves — separately, not as one word for the whole kitchen?
- Is the sink base different from the rest of the run, and how?
- If the interior is melamine or laminate, what core is it bonded to?
- How far do shelves span in the widest cabinet, and how are they supported?
- Do the hinges land in a face frame or in the gable, and with what fastener?
- Is the back structural, and where is the hanging rail?
- What are the exposed edges banded with, and are any raw edges left inside?
None of those is a trick question, and a shop that builds cabinetry answers them without pausing. The pause is the information. Getting the answers in writing is also what makes two cabinet quotes comparable at all, the same argument as reading an itemized estimate line by line.
What we open up around here
The builder-grade kitchens that came with a lot of Hamilton County houses share a pattern. Low-density boxes, thin backs, stapled drawer boxes, shelves that have taken a curve, and a sink base that has been wet at least once. The face frames are often sound, which surprises people, and it is why a repaint can be right in a kitchen whose boxes look tired. Whether that holds in yours is a condition question, not a materials question, and it is the whole of repaint, reface or replace.
The short version
Plywood earns its price in three places: where water arrives, where screws carry load, and where a panel has to span. Particleboard and MDF earn theirs where flatness and paint matter more. A well-built kitchen uses both, deliberately, and whoever built it can tell you which is where.
If you take one thing: ask what the sink base is made of. Small question, long memory.
The kitchen page sets out the two routes we work in — keep the layout and change the surfaces, or change the plan — and either way the cabinet specification is what the number turns on. Kitchens that went both ways are in recent work. If you want somebody to open your doors, press on the sink base and tell you what is in there, ask for an estimate. We look first, then quote.
