Plywood and particleboard don’t have the same reputation as hardwoods and softwoods. But both plywood and particleboard are very useful. And they are much cheaper than most solid woods.
Plywood offers a number of advantages for woodworkers. It is available in wide range of thicknesses and sizes. You can get plywood with any common veneer. Plywood is easy to cut, the only thing it is not suitable for is complicated joinery. Plywood is very stable, cracking, warping and twisting are very uncommon. And yes, plywood is cheap.
Plywood as we know it is a fairly new product, it was introduced in the middle of the 19th century. Plywood is made up of thin sheets of wood veneer. So it is possible to say that plywood is really old, going back to the ancient Egypt. But the modern plywood is as mentioned, much newer, it was invented by Immanuel Nobel. Plywood is made up of wooden layers that are glued together. By making sure that adjacent layers have their grain at right angles to each other, plywood becomes very strong. By using an odd number of layers, the sheet becomes very balanced. The end result is that plywood is stronger than a single piece of wood of the same size.
Like solid woods, plywood is available in both softwood and hardwood varieties. But in the case of plywood, the terms refer only to the face and back layer. Plywood is grouped according to strength and durability. The strongest plywood is called Group 1 for softwood and Category A for hardwood plywood. Group 4 (softwood) and Category D (hardwood) are the poorest grades.
Note that some plywood panels are waterproof, suitable for outdoor weather. Interior grade plywood is able to withstand some moisture.
Plywood has one major shortcoming, the veneer sheets are clearly visible. Fortunately, you have a number of ways of concealing the multi-ply composition.
Particleboard was developed in the 1930s. It was one way of recycling sawmill waste. Particle board is made of a mix of wood particles and synthetic adhesive bonded together under heat and pressure. The cheap price and versatility of particleboard has made it very popular. A lot of sawmills main activity is the production of particleboard. But for many woodworking purposes, particleboard has one problem, it is difficult to work with. Except for multi-layer particleboard, particleboard is not suitable for painting or finishing.
Note that fiberboard, sometimes called hardboard is not the same as particleboard. Fiberboard is made up of wood particles reduced to individual fibers. Fiberboard is much easier to work with than particleboard.