Plywood is a semi-finished product made of layers of wood peeled from the trunk of the tree.
It belongs to the large class of layered or multilayer panels, from which it is distinguished by the cross orientation of the various layers.

In fact, the process of making plywood panels involves “peeling” the tree trunk with a special lathe that can cut a very thin layer of wood (1-3 mm), then gluing the sheets together so that the grain “crosses over.” This intersection causes the strength of the material to be uniform in all directions, because the strength of the wood along the grain does not occur equally in all directions. The crossing of the grain causes the wood’s typically unidirectional mechanical properties to be “offset” in an orthogonal direction, hence the name. Produced since the mid-nineteenth century, it was considered a modern material (the cost of which is even today higher than that of simple planks) and was used for the paneling of furniture, even historicist furniture decorated with impressive carved parts made of solid walnut.

The most commonly used woods for the production of laminated panels are softwoods such as softwoods such as softwood conifers and in particular Spruce, Birch or Poplar, but there are plywoods made from more valuable woods such as Beech, Teak, Okoume and others. There are also plywoods in which only the outer layers are made of more or less thin sheets of fine woods such as those just mentioned or even Walnut, Oak, Rosewood, etc., while the inner layers that make up the bulk of the panel are made of softwoods. In the latter cases plywood is also called melamine faced plywood.
To glue the sheets together you need a simple press as large as the panel, similar or the same as the one used to create particle board. If you use phenolic (water-resistant) glue, you have plywood that is suitable for outdoor use and transportation by sea (such as “Canadian marine” plywood).