A 20 x 26 poster frame requires artwork measuring 20 inches wide by 26 inches high, and the frame’s retaining lip typically covers about ¼ inch on every edge.
The most expensive framing mistake is ordering a frame built for the wrong number. A 20 x 26 poster frame holds a print that measures exactly 20 inches across and 26 inches down — but the frame sitting on your wall right now might be labeled with its outside dimensions instead, which are noticeably larger. Measure the poster, not the old frame, and the rest of the fit falls into place.
Below is the measuring order that works, the overlap that eats into your visible image, and the mat problem that catches people who size a frame before they size the print.
How Do You Measure A Poster For A 20 x 26 Frame?
Pull the poster out of any frame, lay it flat on a hard clean surface, and measure width left-to-right first, then height top-to-bottom. Record the result as width × height in inches — 20 × 26 in this case — and note whether you want it hung portrait or landscape.
Details decide this measurement:
- Smooth out curls and buckling before the tape goes down; a wavy edge reads short.
- Use a rigid ruler or rigid tape measure marked in inches with fine increments.
- Measure to the nearest 1/16 inch when precision matters, and repeat each measurement to confirm it.
- Write down the orientation — a 20 × 26 poster hung sideways is a 26 × 20 frame order.
American Frame’s measuring guidance keeps this simple: measure the artwork’s width and height exactly, and account for mat overlap or canvas depth where those apply. Its frame lip overlaps the artwork by roughly ¼ inch on all sides.
Then read the listing carefully. Look for the terms picture size, art size, opening, sight opening, and outside dimensions — and never assume the biggest number on the page is the artwork size.
| Measurement On The Listing | What It Actually Tells You | What To Do With It |
|---|---|---|
| Picture size / art size | The print dimensions the frame is built to hold | Confirm it reads 20 × 26 in |
| Sight opening | The visible window after the lip overlaps the print | Expect it slightly under 20 × 26 in |
| Outside dimensions | Total footprint including molding and hardware | Use it for wall space, never for artwork fit |
| Mat opening | How much of the poster stays visible through the mat | Size the mat to the artwork, not the frame |
| Frame rebate depth | How much thickness fits behind the lip | Check it for mounted, laminated, or foam-board prints |
| Second supported size | A smaller print the frame accepts with the mat installed | Verify before assuming a full 20 × 26 works matted |
| Included hardware rating | Weight and wall-material limits stated by the maker | Verify on the product page for broad or heavy frames |
Why The Visible Opening Is Smaller Than 20 x 26 Inches
A frame’s retaining lip grips the front edge of the print so it can’t fall through, and that grip covers part of the image. The overlap runs roughly ¼ inch per side, so a nominally 20 × 26 frame can hide a thin border, a signature, or the first letters of edge text.
Frame It Easy describes the same ¼ inch overlap and advises ordering art ½ inch larger in each direction when the desired visible opening has to preserve edge details. Check the manufacturer’s specifications for exact opening dimensions — they vary by product, and no standard chart substitutes for the specific listing.
If the entire print must stay visible, plan for custom framing or accept that the outer quarter inch gets tucked behind the lip. For a print with a wide white border, that overlap is usually harmless. For a full-bleed photo, it isn’t.
Does A Mat Change Your Frame Size?
Yes — adding a mat means sizing up the frame, because a 20 × 26 frame generally cannot give a full 20 × 26 poster any mat border at all.
Mats work by overlapping the paper to hold it in place. American Frame cuts a mat window ¼ inch smaller than the artwork in both directions, producing about ⅛ inch of overlap per side. A mat opening is normally smaller than the poster, and it — not the frame’s outside dimension — determines how much of the image stays visible.
Two workable routes exist. Specify a custom mat opening that accommodates the full image, confirming the mat won’t conceal important edge content. Or buy a standard 20 × 26 frame with an included mat and check the manufacturer’s second supported size, since many such products take a smaller print with the mat installed but a full 20 × 26 poster without it. Once the sizing is settled, our roundup of the best 20 x 26 poster frames compares real options for the fit you’ve confirmed.
What Goes Wrong Most Often
Nearly every bad frame order traces back to one of a handful of slips: confusing outside dimensions with picture size, measuring an old frame instead of the print, reversing width and height, or mixing centimeters into an inch-based listing.
Two more quietly ruin the result. Assuming a nominally labeled 20 × 26 frame has a clear opening of exactly 20 × 26 inches ignores the lip. Adding a mat without sizing up the frame shrinks the visible image twice — once for the mat, once for the overlap.
Thickness matters too. Verify the poster’s thickness against the frame rebate, backing, clips, and turn buttons, especially for mounted, laminated, or foam-board prints that sit deeper than paper. Broad or heavy frames may need wall anchors suited to your wall material, and the manufacturer’s specifications are the place to confirm weight limits and hardware rather than trusting a generic chart. Measure the print once, read the listing’s sizing terms twice, and the frame that arrives will fit the poster you already own.
FAQs
Is A 20 x 26 Frame Measured By Its Outside Edge?
No. A frame sold as 20 x 26 refers to the picture size it holds, meaning the artwork dimensions. The outside footprint is larger because of the molding, glazing, backing, and hanging hardware. Check the listing’s picture size or art size field to confirm which measurement you’re looking at before ordering.
Will A 20 x 26 Poster Show Its Full Image In A Standard Frame?
Usually not quite. The retaining lip covers roughly ¼ inch on each edge, so the sight opening runs slightly smaller than 20 x 26 inches. Prints with white borders lose nothing noticeable. Full-bleed artwork can lose edge detail, so review the manufacturer’s stated opening dimensions if every inch of the image must remain visible.
What Size Frame Do I Need For A 20 x 26 Poster With A Mat?
A larger frame than 20 x 26. A mat overlaps the paper to hold it, and a mat window is cut about ¼ inch smaller than the artwork in both directions, so the frame must exceed the poster size to leave room for the border. Order a custom frame sized for both the print and the mat width.
References & Sources
- American Frame. “How do I measure my artwork?” Source for exact artwork measurement, the ¼ inch frame lip overlap, and mat window sizing.
- Frame It Easy. “How to Measure Art for a Perfect Frame Fit” Source for the ¼ inch overlap and the ½ inch per-direction allowance for preserving edge detail.
- Primark US. “Photo Frame Size Guide” Reference for how frame sizes are labeled in inch-based US measurements.