This story is the introduction and overview for a modular boxes project.
These modular boxes, sometimes called shadow boxes, satisfy various needs, from a catchall in a child's room to a striking showcase for collectibles. Because they stack, you can easily move or rearrange them. Best of all, you can build seven 12x12x12-inch boxes from a single 4x8-foot sheet of plywood.
Measure before cutting
You'd think that a sheet of plywood labeled 3/4 inch thick would actually be 3/4 inch thick. However, that's not always the case. Because much of the plywood sold is of Asian origin (even if it's made with North American wood), it may be slightly smaller than its stated thickness. That inconsistency will throw off your measurements for the sides of these boxes, which are sawed to 10-1/2 inches wide to allow for joining to two thicknesses of 3/4-inch plywood at top and bottom (see the exploded view drawing). So before cutting, measure the plywood's thickness, then deduct twice that from 12 inches for the width of the box sides.
Painting the birch plywood box and adding the distinctive ash veneer tape to the edges (bottom left) creates a distinctive look. For a bright design option, completely paint the box (bottom right). Or you can accent the birch plywood with walnut plugs and veneer (top).
About 4 hours to build seven boxes, plus finishing time
Tape measure, clamps, electric drill/driver, 1-1/2-inch spade bit, 1/16-inch drill bit, table saw or portable circular saw, 40- to 60-tooth blade, handsaw, try square, framing square, hammer, nail set
Sawing, gluing, clamping
Assemble materials; prepare work area.
It's easy to go astray when assembling so many units, so build a clamping jig like the one shown in the following Steps 1-3 to help with assembly. Use it to hold the four sides square to each other while gluing and clamping. You can clamp the jig in just one corner, as shown in Step 3. If one corner is square, the opposite one is also square.
Sand with caution
When finishing these modular boxes, remember that hardwood plywood such as the birch plywood shown has a thin face veneer. If you sand too heavily in one area, it's possible to sand right through the veneer, an error that will show through the final finish. Always maintain a light hand with abrasives, even those with fine grit. Most plywood is fairly smooth to begin with, especially on the face side, so it doesn't take much sanding to prepare a surface for finishing.