Pretty much all of the last 4 centuries of classical woodworking and furniture design is a result of coping with the annual shrinkage and expansion of wood. 1
Plywood is layers of wood glued at right angles, so it doesn’t expand or contract. It fundamentally changed the nature of wood working and design. 2
Plywood did to classical woodworking design what steel-reinforced concrete did to architecture: Blew its mind, kicked it to the curb, made irrelevant all of the delightful constraints that gave interior and furniture design its soul and beauty. 3
Plywood is a manufactured wood made with big machines not coincidentally arriving concurrently with other power tools for woodworking. 4
Woodworking machines and machine-made wood killed off a thousand years of wood working know-how. 5
Back then, the “Arts and Mysteries” of woodworking were passed down via the guild system: apprentices taught by journeymen supervised by masters. 6
Very few plans of pre-industrial furniture survived. Interestingly, lots of other paperwork from then did. Odd, until you realize that financial ledgers were needed but pre-industrial woodworking wasn’t done with plans. 7
That old furniture (and doors, windows, wainscoting, stairs, etc) were made to proportions rather than to plans. That method of proportional design is what was lost with the advent of plywood & power tools. 8
Once you learn proportional design you see it everywhere and in everything. Until you learn it, you are blind to it. 9
Simple proportions: 1 to 1, 1 to 2, 2 to 3. Or divide a piece of furniture into thirds or fifths or seventh or tenths and watch how everything falls into that grid. 10
Wood expands in the wet season about 7% across the grain, about 3% beside the grain, and 0% along the grain. Everything about furniture design is a mechanism for coping with that. 11
(In most of the world, the wet season is the summer, and the dry season is winter. In California—a Mediterranean desert—it’s the other way around.) 12
If you built a door out of planks fastened side to side, it wouldn’t fit its frame for 6 months out of the year. That’s a tough problem. 13
So joiners would build a frame of wood with the (non-expanding) grain of the wood aligned with the critical door dimensions: horizontal across the width and vertical along the sides. They then inserted a free-floating panel in grooves cut into the outside frame. 14
The horizontal pieces kept the width constant year-round, and the vertical pieces did the same with the height. The panel was not glued, screwed, pinned, or nailed, but it floated free, so it could expand and contract without penalty every year. 15
Newbies come along and buy a craftsman built house and—not understanding classical woodwork—paint the doors. Next season, the door cracks because the paint acts as glue, preventing the panel from shrinking without penalty. 16/
