An A3 frame is designed for A3 prints, which measure approximately 11.7 x 16.5 inches (29.7 x 42 cm). That’s the interior print size the frame is meant to hold.

• Orientation: A3 works both portrait and landscape, so most frames hang either way.
• Viewable area: The visible window is typically a bit smaller because the frame’s inner lip overlaps the edges to keep your print in place.
• Tip for measuring: Measure your print edge to edge and match those measurements to the listed “print size” (not the outer frame dimensions).

On our site, you’ll see A3 frames labeled with both inches and centimeters to make sizing easier.

If you want a mat around an A3 print, you’ll usually step up one frame size and use a mat cut for A3.

• Without a mat: Choose a frame labeled A3 (11.7 x 16.5 in / 29.7 x 42 cm).
• With a mat border: Consider a larger frame (often one size up, like A2) paired with a mat opening sized for A3.
• Mat openings: Openings are typically cut slightly smaller than the print to hold it in place, which helps hide the paper edges.
• Pro tip: Check the product details for “mat for A3” or “fits A3 with mat” to confirm compatibility.

They’re close in size but not the same. A3 is about 29.7 x 42 cm, while 30 x 40 cm frames are shorter and have a different aspect ratio.

• Fit: An A3 print is usually too tall for a 30 x 40 cm frame without trimming or visible cropping.
• Aspect ratio: A3’s shape is different from 30 x 40 cm, so edges may gap or clip if forced.
• Better match: Look for frames labeled A3 (11.7 x 16.5 in / 29.7 x 42 cm) for a cleaner fit.
• Workaround: A custom-cut mat could adapt a 30 x 40 cm frame, though results vary depending on the mat layout.

The simplest way is to use a mat sized for A4 inside an A3 frame.

• Frames with mats: Many A3 frames include a removable mat with an opening for A4 (8.3 x 11.7 in). That keeps your smaller photo centered and tidy.
• If no mat included: Add an A3-to-A4 mat separately or place a backing board behind the photo for a border effect.
• Fit details: Mat openings are often cut slightly smaller than A4 to hold the photo edges.
• Orientation: Match the mat orientation (portrait or landscape) to your photo for best results.

Both protect your A3 print, but they offer different benefits.

• Acrylic/plexiglass: Lighter in weight and shatter-resistant, which can be helpful in high-traffic areas. It may scratch more easily, so use a soft cloth and mild cleaner.
• Glass (including tempered): Feels solid and resists scratching better. Tempered options add durability. It’s heavier and can break if dropped.
• UV options: Some acrylic and glass fronts include UV-filtering features that can help reduce fading over time.
• Cleaning: For acrylic, avoid ammonia-based cleaners; use a microfiber cloth and gentle solution. For glass, standard glass cleaners are commonly used.