From screen image to print: a checklist in the right order

Confirm trim width and height, bleed on all sides, recommended resolution, color mode, and accepted format. Trim is the visible area after cutting; bleed extends beyond the cut line to absorb cutting variation. Confusing them can put copy too close to the edge or make the export too small.

For example, A4 trim is 210 × 297 mm. With 3 mm bleed on every side, the file canvas is 216 × 303 mm. Text and logos still need to stay inside the safe area; bleed is not a safe margin.

The formula is pixels = mm ÷ 25.4 × DPI. A4 is about 2480 × 3508 px at 300 DPI and 1240 × 1754 px at 150 DPI. Software rounding can differ by one pixel without changing the decision.

Changing “72 DPI” to “300 DPI” in an editor changes only a tag if pixel width and height stay the same. What matters is whether existing pixels ÷ target inches produces enough effective DPI for the printer.

If the source exceeds the pixel requirement, resize proportionally and inspect sharpness at final size. If it falls short, interpolation creates more pixels but cannot recover missing texture. Faces, fine type, and QR codes need review at 100% or on a physical proof.

High-quality JPG usually suits photos; PNG suits transparency, line work, or lossless graphics. WebP is useful online but may not be accepted by a print workflow. Compression should follow visible quality and delivery limits, not a smaller KB number at the cost of repeated re-encoding.

Resizing, cropping, and format conversion can change pixels and metadata, so calculate effective DPI again on the final export. Check that the canvas includes bleed, key content stays safe, text is sharp, and orientation is correct.

These tools can verify geometry, pixels, and effective DPI. They cannot validate CMYK conversion, spot colors, total ink coverage, font embedding, or press behavior. For a production run, follow the printer template and a physical proof.