I worked for a remodeling contractor for many years and installed cabinetry built by a variety of cabinet makers. They all built their cabinet boxes differently which provided me with quite an education. Not only did I learn how they made their cabinets but also what material they used. There are two basic styles of cabinets; euro style and face frame. There are three basic types of material typically used; melamine, vinyl wrapped press board and cabinet grade plywood. These materials are usually offered in 1/2” or 3/4” thicknesses.
The esthetic of euro style cabinets is that all you see are doors and drawer fronts. Euro is short for European but one could say they look very Scandinavian with it’s clean lines and boxiness. To the best of my knowledge, all euro style cabinets are made out of melamine and the front of the boxes are edge-banded with a wood veneer to match the doors. Melamine is a very straight material that normally doesn’t warp with ambient humidity. But it’s made up of wood dust, glue and formaldehyde then wrapped in vinyl. Not environmentally conscious and does not hold up to water. In fact, in my experience, melamine acts like a sponge and looses it’s molecular structure when in contact with water. Which is inevitable when used for kitchen and bath cabinets.
This simply means that the cabinet box has a frame of solid wood at the face, usually 1 1/2 inches thick, that keeps the box square and true. Even after installing the doors and drawer fronts you will see some of the frame which will usually be the same wood as the doors. When building face frame cabinets one can use any variety of materials. The material I’ve found to work best and holdup to water is a pre-finished birch plywood that’s 3/4 of and inch thick. Not only does it look nice when you open the door, but it’s about a third of the weight of melamine which helps greatly when hanging upper cabinets on the wall and it creates less strain on the installation fasteners.
In addition, when building cabinet boxes I like to cut a shallow groove along the top and bottom of the cabinet sides so that I have an entire one inch of wood to wood glue surface. This serves to create a solidly constructed cabinet that won’t ever break apart with time, water or miss use.