How to Frame a Picture | Size, Matting, and Conservation

Frame a picture by measuring the artwork edge to edge first, then choosing a frame that matches the piece exactly or adds room for a mat.

Getting the size right matters more than any other step. A frame that’s too small crops the image, while one that’s too large leaves the artwork loose and unstable. The process for picture framing starts with one measurement, then branches into a few simple decisions about mats, materials, and hanging.

Measure the Artwork Before You Buy Anything

Measure the exact height and width of the artwork edge to edge before shopping for a frame. This single step prevents most framing mistakes, and it’s the one measurement that determines every other choice you’ll make.

Use a ruler or tape measure and record the dimensions in inches. Standard US frame sizes include 4×6, 5×7, 8×10, 11×14, 16×20, and 24×36 inches, so compare your numbers against those common options first. If your piece is a common size, an off-the-shelf frame will likely fit.

Match the Aspect Ratio to Avoid Cropping

Choosing a frame by overall size alone is the most common mistake rookie framers make. A print’s aspect ratio — the relationship between width and height — must match the frame’s opening, or part of the image disappears under the lip.

Frames typically cover about 2–3 mm of the print’s outer edges, so an exact match still loses a sliver of the image. That lip is normal and expected, but a mismatched aspect ratio loses far more. An 8×10 print belongs in an 8×10 frame; putting it in an 11×14 frame without a mat leaves it floating and unstable, and trimming it to fit destroys the piece.

Use a Mat When the Frame Is Larger

A mat solves the size gap elegantly. Measure the mat’s window to match the artwork, not the frame’s outer edge.

When the frame is larger than the artwork, a mat or spacer is required to keep the piece from shifting. Skipping both leaves the artwork loose inside the frame, which leads to rattling, creasing, and eventual damage.

Conservation Framing for Paper Artwork

For valuable or paper-based works, conservation framing protects the piece for decades. The layer order matters: backing board, mounted artwork, mat board if used, and glazing on top. Use a strong frame, appropriate glazing, and a sealed backing board to keep dust and moisture out.

Conservation guidance from the State Library Victoria recommends reversible, conservation-safe techniques. That means acid-free, lignin-free, and UV-protective materials, and no adhesives, heat-based processes, or spray mounts. Those methods make future removal difficult and can harm the artwork over time.

Keep framed works away from direct sunlight, heat sources, and humidity, which all degrade paper and fade pigments over the years. When hanging, use two hooks — one at each side of the frame — for stability, especially on larger pieces.

Decorative framing for posters and inexpensive prints can skip some conservation steps, but the size-matching principles still apply. Measure first, match the ratio, and use a mat when the frame runs larger than the piece. If you’re ready to shop for a frame, our roundup of the best picture frames compares top-rated options for common print sizes.