Plywood is made from a number of slices of veneer which are laminated with glue to bond them together. Each layer of veneer is turned with the grain direction at 90° to that of the adjacent layers (see Fig 2.7). As a guide, good quality ply consists of a comparatively high number of thin slices of veneer, while low quality ply has a relatively small number of thick layers.

Plywood is available in a wide variety of sheet sizes, thicknesses and wood types, each intended for different applications. The thickness ranges from '/i6m (2mm), intended for model-making, to at least lin (25mm), which I have seen used for table tennis tops. Both hardwoods and softwoods are used; for furniture making, a softwood ply with a slice of high quality hardwood on the face is often a good choice.

Plywood has a number of advantages over large boards made from joining solid wood planks. Strength, flexibility and price are among its assets, but the principal benefit is stability, as it will not shrink or stretch under most conditions. The applications for which I find it most useful are drawer sides and bases, and the backs of cupboards.

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