The Use of Plywood

Let's talk about plywood now that MDF is never going to be used again in your furniture projects.  Plywood is made of solid wood strips glued up in width, with two or more veneer layers on both faces (lumber core) or multiple veneer layers with every other layer 90 degrees to the above layer.  The layers vary from roughly 1/4" to 1/16" thick and 5 to 15 layers of hard or soft wood with one layer of more or less finished veneer on both faces, depending on the grade (veneer core) 

The positive attributes of plywood, especially lumber core, and Baltic birch or apple ply (both usually 15 layers of hardwood) are it is relatively light, strong and fasteners, joinery and glue-ups work pretty good.  Also, there is not much dimension change with an increase or decrease in humidity. 

The disadvantages of plywood are the surfaces, and especially the edges, which damage easily.  Also, if you want to use solid wood and plywood together, they are difficult to match finishes, because the cut of the veneer produces different grain patterns and solid wood oxidizes differently than veneered surfaces that are only 1/60" to 1/30" thick.

Solid woods like cherry and mahogany get quite a bit darker as they age, while walnut becomes lighter, kind of a golden brown.  Veneered plywood changes very little, the change being hardly noticeable.

My conclusion has been if I am going to use plywood in a project, it is only used on the interior of a project, such as division walls, bottoms, backs, etc.  All exterior frames, panels, doors, drawers, including drawer sides and all shelving are solid wood.  This combines the strength and ease of working in plywood on the interior parts of the project, and the furability and beauty of solid wood on the exterior and other areas of the project, where wear is a concern.   Note:  Don't use plywood for any shelving, especially adjustable shelving.  Over time, plywood will sag.  Solid wood can be repaired and refinished over and over, giving it longivity other materials don't have.  One other concern is to be careful when combining solid wood and plywood because of the difference in expansion and contraction, which I will go into more in the future.