Make & keep
Why a photo strip looks sharp on screen but soft in print
Compare the source pixels with the size you asked the printer to make.
A phone can show a small image beautifully while a much larger print exposes its limits. Begin with the file’s actual pixel dimensions and the intended physical dimensions, rather than the size of the preview window.
Work through one size
Our example file is 600 by 1800 pixels. At a chosen 300 pixels per inch, it corresponds to 2 by 6 inches. Printing it at 4 by 12 inches uses 150 pixels per inch. The calculation changes the sampling density; it does not add detail that the file never contained.
Do not let metadata decide for you
MDN notes that browser canvas exports can encode 96dpi resolution metadata for formats that support it. That tag does not force a particular paper size in the print dialogue. Choose the physical dimensions yourself and inspect scaling.
Evidence: Technical documentation
Proof before enlarging
Print a replaceable test and look at a face, lettering and the border. If the source is an old scan, return to its best available master before enlarging a compressed sharing copy. Keep the full strip and any close-up crops as separate files so improving one presentation does not discard the original record.
Sources & further reading
Sources for the specific facts and product descriptions above. Our worked examples, interpretations and practical suggestions are original editorial guidance.
- MDN — HTMLCanvasElement.toBlob()Technical documentation