A4 is the most familiar print format: it fits ordinary printers, photo paper and frames, so an A4 collage is easy to hang on a wall, slip into an album or give as a gift. The canvas opens straight away in 210×297 mm portrait proportions, so you won't have to crop the photos to the sheet at the last moment. Pick a ready layout or build your own — the photos flow into the cells and you fine-tune the crop of each.
Resolution matters for print: the A4 layout is built for high quality, and the PDF export saves the collage at 300 DPI — the print-shop standard where pixels don't show. You can also download PNG or JPG for home printing. The background, gaps between frames and backdrop colour are adjustable, and the result is saved with no watermarks, free and without sign-up.