What's inside
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A small shadow box is a good first mitred-frame project: the parts are short, the materials are inexpensive, and the box can hold a pressed flower, a medal, or another light keepsake. The tricky part is keeping four mitres closed and square while the glue sets. Build the box first, then fit a frame to its front.
Contents
Choose the size and depth
For a first build, aim for an outside frame size around 8 by 10 inches and a depth of 1½ to 2 inches. That is large enough for a small display but manageable to clamp. Decide what goes inside before cutting: allow room for the object, a backing board, and any spacer that keeps the glass from touching the contents.
A straightforward layout uses a mitred wooden frame, a shallow plywood box behind it, clear glazing at the front, and a removable back. Use ¼-inch plywood for the box and back; ⅛-inch hardboard is also suitable for a flat, removable back. If the object is unusually heavy, add a sturdier hanging system and test the finished box on a secure wall fixing.
Materials and tools
You will need straight, dry stock about ½ to ¾ inch thick and 1½ to 2 inches wide for the frame, ¼-inch plywood for the box, glue, and clear acrylic or glass. Softwood is inexpensive and easy to cut, though dents and rough grain show under a clear finish. A hardwood such as poplar or maple costs more but gives a cleaner, harder edge.
A mitre saw is convenient, but a mitre box and fine-tooth backsaw can do the job for one small frame. A hand mitre box and backsaw are a sensible low-cost choice if you do not already own a saw. For repeat projects or longer stock, a well-set mitre saw is faster; it is not automatically more accurate if its fence or blade is out of square.
Useful extras include a combination square, clamps, sandpaper, and a frame band clamp. A band clamp applies even pressure around all four corners, but ordinary clamps and scrap cauls work if you check the frame carefully. For glazing, acrylic is lighter and less likely to break; glass resists scratching better and usually looks clearer.
Build the shallow box
First measure the frame’s intended inside opening. Cut a plywood bottom to that size, then cut four side strips to make a box that fits behind the frame. For a frame with an 8-by-10-inch outside size and 1½-inch-wide rails, the opening is about 5 by 7 inches; make the box to match that opening, not the outside dimensions. Dry-fit the parts before gluing.
Glue the side strips around the bottom, keeping the box square. Check both diagonals: if they differ by more than about ⅛ inch, adjust the clamps before the glue grabs. Let the box dry flat. If you want a removable back, cut it to fit the rear opening and retain it with small turn buttons, screws, or a shallow rabbet. A glued-on back is simpler but makes changing the display harder.
Cut and dry-fit the frame
Cut four frame pieces with 45-degree mitres, measuring the long points to the outside dimensions. Mark each piece clearly so you do not accidentally make two left-hand or two right-hand cuts. Keep the same face against the fence for every cut. A small stop block helps match opposite rails, but confirm the first pair before cutting all four.
Before gluing, put the frame together on a flat surface. The corners should close without force, and the diagonals should match. A visible gap at a mitre usually means the cut is not exactly 45 degrees, the stock shifted, or the ends were measured from inconsistent points. Do not try to pull a bad joint shut with excessive clamp pressure: the frame can bow or slide out of square. Recut a slightly long piece, or sand a high spot carefully.
| Glazing choice | Best for | Trade-off |
|---|---|---|
| Acrylic sheet | Lightweight displays and rooms where breakage is a concern | Scratches more easily; peel protective film only after handling |
| Glass | A crisp, scratch-resistant view | Heavier and breakable; have it cut to size rather than scoring it without practice |
Glue and assemble the frame
Apply a thin, even coat of wood glue to each mitre. Bring the corners together with a band clamp, or use pairs of clamps with scrap blocks to protect the wood. Check the diagonals and use a square at the corners while tightening. Wipe away squeeze-out with a damp cloth before it dries, especially if the frame will be stained; dried glue can leave pale patches that stain will not hide.
For extra strength, add small brads or a biscuit at each corner if you have the tools and enough rail width. On a small box holding light contents, careful glue joints are often enough. Do not add fasteners so close to the edge that they split the mitre. Leave the frame clamped for the glue maker’s stated time, then allow it to cure before sanding or loading it.
Fit the glazing, finish, and hang
Once the glue has cured, sand the frame lightly, starting around 120 grit and finishing at 180 or 220. Avoid rounding over the mitred corners. Test-fit the frame over the box; it should sit flat without rocking. Attach it from behind with small screws through the box sides into the frame, or use suitable brads. Predrill near the ends to reduce splitting.
Fit the glazing into the front opening, followed by the display and backing. Leave a little clearance so the contents are not crushed. Finish bare wood with a clear oil or varnish, or paint it after testing on an offcut. Install two hanging points or a rated picture hanger suited to the finished weight. Before hanging, test the hardware with the box resting on a bench; a heavy glass front or dense keepsake can make a small frame surprisingly weighty.