How to Choose a Shadow Box Frame: Size, Depth and Where to Buy
A shadow box frame is chosen on two numbers: the internal opening must match your design size, and the internal depth must exceed your finished stack. Almost every frame problem comes from the second number, because retail listings quote the outside of the frame and your stack has to fit the inside.
Internal Depth Is the Only Number
Here is how the failure goes. You buy a frame listed as 5 cm deep. You build a stack you calculated at 4 cm. The back will not close.
The 5 cm was the external depth - the whole moulding measured from the front face to the back edge. Inside that, the rebate lip, the glass and the backing board have eaten 10-15 mm before your paper goes anywhere near it.
Take the back off, put a ruler inside, and measure from the back of the glass to the inside face of the backing board. That figure is your working budget. Nothing on the packaging tells you it.
Calculating Your Stack
- Count your gaps, not layers. Six layers means five gaps.
- Gaps x spacer thickness. Five gaps x 5 mm = 25 mm.
- Add the paper itself: 6 layers x 0.25 mm = 1.5 mm.
- Add the LED strip and its backing: typically 8-12 mm.
- Add 5 mm of headroom so the backing board seats without compressing the stack.
- Total for a standard six-layer build: about 45 mm. Buy a frame with 50 mm internal depth or more.
Full working in the spacer guide, which also covers what to do when the total comes out too thick.
| Build type | Layers | Typical internal depth needed |
|---|---|---|
| Pop-up light box | 3-5 angled | 40-50 mm |
| Standard light box | 6 layers, 5 mm spacers | 50-60 mm |
| Dense multi-layer | 9-10 layers, 2-3 mm spacers | 50-60 mm |
| Bold statement piece | 4 layers, 7 mm spacers | 55-65 mm |
| Paper spacers, shallow | 6 layers, 2 mm spacers | 30-40 mm |
If your stack will not fit, switch from foam board to paper spacers before you buy a bigger frame. Going from 5 mm to 2 mm across five gaps saves 15 mm - usually enough.
Common Sizes and What Fits
| Frame opening | Fits designs sized | Notes |
|---|---|---|
| 8 x 8 in (20 x 20 cm) | 8x8 in square designs | The most common size in our catalogue |
| 8 x 10 in (20 x 25 cm) | 8x10 in designs | Best for landscape and portrait scenes |
| A4 (21 x 29.7 cm) | A4 designs | Widely available outside the US |
| 12 x 12 in (30 x 30 cm) | Statement pieces | Deep versions are harder to find and pricier |
| 6 x 6 in (15 x 15 cm) | Small keepsakes | Good for pet memorials and bedside pieces |
Every product listing states the finished size. Do not resize a design to fit a frame you already own - scaling breaks the spacer margins and pushes fine detail below your machine's cutting threshold.
Glass, Backing and Mounting
Glass - a judgement call rather than a rule.
- Keep it if the piece will be handled, is going in a kitchen or hallway, or will sit somewhere dusty. Dust in a layered stack is effectively impossible to clean.
- Remove it for maximum brightness and truest colour. Glass adds a faint reflection and a slight green cast on cheaper frames.
- Acrylic is the compromise - lighter, safer around children, slightly less optically clean.
Backing board - your LED mounting surface. If it is flimsy card, replace it with a piece of foam board cut to size; a sagging backing lets the whole stack shift.
Cable exit - drill or punch a small hole in the backing board near a bottom corner before assembly. Trying to route a cable after the stack is in is how stacks get disturbed.
Where to Buy
- Craft chains - reliable 8x8 and 8x10 shadow box frames, and they discount often. Depth is usually adequate but check.
- Flat-pack furniture retailers - cheap deep box frames in standard metric sizes. Quality is variable; the backing is often thin.
- Online frame specialists - the only realistic source for unusual sizes or genuinely deep frames, and the only place that reliably publishes internal depth.
- Charity and thrift shops - deep frames turn up regularly and cost almost nothing. Ignore the picture inside.
Deep shadow box frames are the November bottleneck. Stock thins and prices climb through Q4. Order them alongside your cardstock - see the planning calendar.
Making Your Own
Two routes when nothing off the shelf fits.
Paper or card frame templates. Cut on the same machine, in the same session, from the same stock. Lightweight, cheap, and they match the piece by definition. Several are in the Material collection. Best for smaller pieces and for lanterns that only need a base.
Timber box frame. Four mitred lengths of 60-70 mm planed timber, glued and pinned, with a rebate routed or a fillet strip glued inside to hold the backing. Straightforward if you have a mitre saw, and it is the right answer for a 5th anniversary wood gift.
Measure the Inside, Buy One Size Deeper
Two habits eliminate almost all frame problems: measure the internal depth with the back off, and when you are between two options, buy the deeper one. Excess depth is invisible in the finished piece. Insufficient depth means starting again.
Frequently Asked Questions
What size frame do I need for a paper cut light box?
Match the frame's internal opening to the design's stated finished size, and make sure the internal depth is at least 8 cm for a standard six-layer build. Most 8x10 inch shadow box frames work.
How deep should a shadow box frame be?
At least 8 cm internal depth for six layers with 5 mm spacers plus an LED strip. Shallower frames work for pop-ups and for builds with fewer, thinner-spaced layers.
Why does my finished stack not fit in the frame?
Retail listings quote external depth, which is typically 10-15 mm more than the internal depth once you account for the rebate and glass. Measure the inside yourself with the back off.
Should I keep the glass in a shadow box frame?
Keep it if the piece will be handled or is going somewhere dusty. Remove it if you want maximum brightness and the truest colour from your LED - glass adds a slight reflection.
Can I make my own frame?
Yes, and for unusual sizes it is often the only option. Paper and card frame templates are available, or a simple mitred timber box is a straightforward build if you have the tools.
Designs to Start With
Three files that suit what this guide covers - every download includes SVG, DXF, print-and-cut PDF and a PNG preview.
If none of these is quite right, start from the Vektor Kraft home page and work down by format, or browse what other people are cutting.
Frame and spacer templates
Cut your own frames and spacers from the same stock as your layers.
Get frame files