A4 vs Letter Scaling for Printer Test Pages
A4 and US Letter are close in size but not identical. Browser “fit” options, non-printable margins and printer-driver scaling can resize diagnostic grids and line widths, which matters when you compare two prints.
A4 and Letter Are Different Shapes
A4 is 210 × 297 mm. US Letter is 8.5 × 11 inches (215.9 × 279.4 mm). A layout can fit both while still being scaled slightly differently by the browser or driver.
For a Before/After Diagnostic, Consistency Matters Most
If your goal is to compare a print before and after cleaning/alignment, use the same paper size, scale, margins, quality mode and browser both times. A consistent 97% scale is more useful for comparison than switching between 100% and “fit” between prints.
When to Prefer 100% or Actual Size
Use 100%/actual size when you are evaluating line widths, ruler-like marks or alignment geometry and the sheet fits within the printer's printable area. If the printer clips content, use fit-to-page but record that scaling was applied.
Background Graphics
Color blocks and gradients depend on background printing. The site's print CSS requests exact print colors, but browsers and drivers can still have a separate background-graphics option. If blocks disappear, check that option before diagnosing the printer.
PDF vs Browser
If a browser print behaves unexpectedly, compare the downloadable PDF at the same paper size and scale. If the PDF and browser output differ while the printer's internal report is normal, rendering or driver settings deserve attention.