Extra Deep Box Frames: Options and Costs

An extra deep box frame is any box frame built past the everyday 30mm to 50mm range. At our workshop that runs to 150mm and beyond, and there is no fixed limit: each profile is machined from raw timber to whatever depth the object needs, with allowance for glazing, mount board and sub-frame.

This guide covers which objects genuinely need the depth, how the construction changes as a frame gets deeper, the glass question, and what it all costs. If you are untangling terminology first, our comparison of box frames and shadow boxes explains why the two names mean the same frame.

What needs the extra depth

Most box framing sits comfortably under 50mm: a medal group needs around 30mm and a folded shirt 35mm to 50mm. The deep end of the range is for objects with real height, or displays where the arrangement itself has depth:

• Dried bouquets, which can need 60mm or more once arranged in relief rather than pressed

• Garments displayed with volume rather than folded flat, from christening gowns to full wedding dresses

• Ceramics, models and other sculptural objects

• Pieces where a deliberately deep case is chosen for effect, so a small object floats in space like a gallery exhibit

How depth changes the build

A deep frame is not a standard frame with taller sides. The profile is machined as one piece from raw timber, because even a 5mm difference changes how the object sits behind the glass. Corners are spline joined for strength, and once a case gets large as well as deep, a sub-frame keeps the structure rigid and can double as the split-batten hanging system.

Inside, paper-wrapped spacers hold the glazing off the object and mounting stays fully reversible: Japanese museum tags, conservation stitching and custom supports, with no glue, no staples and no nails touching the piece. Most builds are solid Tulipwood, and for very large or heavy cases we switch to welded aluminium, which holds its shape at depth with a slim front face.

Deep box frames with glass

Yes, a deep box frame can be glazed with real glass, in 2mm to 6mm thicknesses and in standard, anti-reflective or museum grade with UV protection up to 99.9%. The practical consideration is weight. Glass gets heavy quickly as a case grows, so for larger deep frames we usually recommend acrylic, which looks identical on the wall at a fraction of the weight. For small and medium cases, glass is a perfectly good choice and some clients prefer its feel and scratch resistance.

Long box frames

The same construction also produces long, narrow cases, where one dimension stretches rather than the depth. The engineering concern shifts: across a long span the sub-frame does the work of keeping the case straight and the glazing supported. If your object is long rather than tall, the frame is built the same way, specified around the span instead of the depth.

What an extra deep box frame costs

Bespoke box framing starts from around £350, and depth on its own does not change that dramatically. The price moves with overall size, glazing grade and finish, so a deep but compact bouquet case sits near the starting point while a large, deep acrylic case is a bigger build. Most projects are completed in two to four weeks. For the wider picture on pricing, see our guide to how much custom framing costs.

Every deep box frame we build is made to order in our Bollington workshop, as they have been since 1974, with a 5 year guarantee. Send us a photo of the object and its rough dimensions, including the height, and we will quote the case around it.