How we check dimensions and results

Results should be explainable and repeatable. The tools show the calculation and distinguish a digital document from a physical print.

Units and resolution

We use 25.4 millimeters per inch. Effective PPI is the number of pixels used divided by the printed length in inches. Fill mode accounts for its centered crop; Fit mode uses the area actually occupied by the image.

Minimum pixel counts round upward to meet your selected reference. The preview and print document use the same paper dimensions, margins, copy count and fit mode.

What the tests cover

Automated tests check conversions, PPI, aspect ratios, crops, copy counts, page boundaries and the dimensions written into the print document. These are mathematical and digital-output checks. They are not a test of your printer.

Preview limitations

The on-screen preview is proportional, not a life-size ruler. The print dialog can override scale, margins and paper. Use 100% and measure a first copy with a ruler. Your source image, printer and paper also affect the finished result.

How guides are prepared

Texts are prepared with AI assistance and checked against their mathematical examples and linked sources. We do not present an invented professional biography, printing certification or fictional physical-printer test.

References

W3C: CSS units and physical lengths
Adobe Photoshop: image size and resolution
Adobe: printing large documents and adjusting scale