What Is an A3 Photo Printer? A Complete Guide to A3 Photo Printing

A3 sits at roughly double the area of A4 (standard US letter size), which is why portrait photographers, designers, and small studios buy these machines. This guide covers the real dimensions, ink counts, connectivity, and border limits that shopping listings rarely spell out.

What Size Is A3 Paper, Exactly?

A3 paper measures 297 × 420 mm — about 11.7 × 16.5 inches, double the area of A4 and far larger than 8.5 × 11 inch letter paper.

The trap is A3+ (also written A3 plus), which is not the same sheet. A3+ refers to the wider borderless format, and Canon lists it at 329 mm wide on the imagePROGRAF PRO-300. Borderless output is model-specific, and on some printers limited to A3+ — confirm the exact width the machine accepts before buying.

Canon’s PRO-300 also accepts manual feed media up to 990.60 mm long, opening the door to panoramic prints. That capability varies by model, so verify it as a spec.

How Does An A3 Photo Printer Differ From A Regular Printer?

Ink systems are the biggest difference. Canon describes its A3 professional photo printer lineup as using 8-, 10-, or 12-ink systems aimed at photographers from advanced amateurs to top professionals. A typical home office printer runs four inks or fewer. The extra cartridges — often including a gloss optimiser — widen the color range and smooth out tonal transitions that cheaper machines band or dither.

Resolution matters too, though raw dpi numbers need context. Canon’s PRO-300 lists a maximum resolution of 4,800 × 2,400 dpi across 7,680 nozzles. That nozzle count affects droplet placement and speed as much as detail, and explains why these printers cost more to run than a document machine.

Paper handling also differs. Photo-grade media like Canon’s Photo Paper Pro Platinum, Photo Paper Plus Semi-gloss, and Photo Paper Pro Luster come in A3 and A3+ sizes, and support varies by model. Thickness limits, tray count, and direct-feed options differ across the range, so match the printer to the paper you plan to use.

What Specs Should You Check Before Buying?

Start with footprint: Canon lists the imagePROGRAF PRO-300 at approximately 639 × 379 × 200 mm and about 14.4 kg — substantial for a desktop, so measure your table first.

Connectivity comes next. The PRO-300 connects to a PC or Mac over Wi-Fi or Ethernet, and Canon’s product pages point users to drivers, software, firmware, and online support. Download the current driver before setup.

Two caveats: some models are region-specific — the specs here come from Canon’s CNA/Asia and Europe pages, so US availability, pricing, and bundled accessories may differ. Reliable current US retail pricing was not available in the sources reviewed, so confirm any price with a US retailer.

Once you know which specs matter, comparing real models side by side is the next step — our roundup of the best A3 photo printers we tested covers current options and how they stack up.

What Should Most Buyers Do Next?

Confirm three things before you commit: the exact borderless width you need, the specific paper types you print on, and whether the model is sold in your region. Pull the current data sheet from the manufacturer’s page — Canon’s imagePROGRAF PRO-300 specifications page is a good example of the detail to look for.

After that, the decision narrows to ink cost, footprint, and whether you need Ethernet for a studio setup or Wi-Fi is enough.