How to Measure a Canvas for a Floating Frame
I build floating frames for a living, and the question I get more than any other isn't about wood. It's about measurement. "My canvas says 16x20, do I just order 16x20?"
Almost. Here's how to measure it right, in about two minutes, with the tape measure you already own.
Why "16x20" isn't always 16x20
A stretched canvas is fabric pulled over wood bars by hand. The fold at each corner adds a little bulk. The bars themselves can vary by a hair from the listed size. And canvas moves, it was stretched under tension, and tension does what it wants.
A floating frame has no glass and no lip covering the edges. The canvas sits inside it with a small shadow gap all the way around. That's the whole effect — your art, suspended in hardwood. Which means the frame has to be built around your actual canvas, not the size printed on the label.
Step 1: Width and height
Lay the canvas face up. Measure the width at the top, the middle, and the bottom. Then the height at the left, center, and right.
Use the largest number you find. If the top reads 20" and the bottom reads 20 1/8", the canvas is 20 1/8" for framing purposes. Measure over the face of the canvas, edge to edge, including the corner folds, the frame has to clear them.
Write your measurements to the nearest 1/16". Don't round down. A frame can absorb a canvas that's a touch small. It can't absorb one that's too big.
Step 2: Depth
Set the canvas on its edge and measure from the back of the stretcher bar to the front face of the canvas. Most canvases come in around 5/8", 3/4", or 1 1/2" (the deep "gallery wrap").
Depth decides how your art sits in the frame. Matched to your canvas, the face of your painting lands right where it should, at or just below the front edge of the frame, floating in that line of shadow. Too shallow a frame and the canvas pokes out past the front. It happens with off-the-shelf frames all the time.
Step 3: Check the diagonals
Measure corner to corner both ways. If the two numbers match, your canvas is square. If they're off by more than about 1/8", it's slightly trapezoidal, common with hand-stretched pieces, and nothing to panic over. Note it when you order. A consistent gap hides a lot; I can plan for it.
The three mistakes I see most
Trusting the label. The listed size describes the stretcher bars, not the finished canvas. Measure the real thing.
Measuring one spot. Canvases bow. Three measurements per side catches it.
Skipping depth. Width and height get the frame the right size. Depth gets your art sitting right in it.
What I do with your numbers
Here's the part that should take the pressure off: every frame that leaves my shop is built to order, for one specific canvas. You send me the largest width, the largest height, and the depth. I mill the frame from rough walnut, cherry, maple, or white oak, size the opening for an even shadow gap around your piece, and match the depth so your art sits where it belongs. If anything about your measurements looks odd, I'll email you before I cut a board. I read every message myself.
You measure. I build. That's the whole arrangement.
Ready to frame it? Start with the Canvas Floating Frames and pick your hardwood.