How to print at Actual size or 100 percent
Keep the PDF's exact dimensions by disabling printer scaling and checking one measured physical sample.

Turn off printer scaling
Open the generated PDF in a current browser or trusted PDF viewer. In the print dialog, choose Actual size or enter 100 percent scale.
Do not choose Fit, Shrink oversized pages, or Scale to printable area. Those settings change the physical dimensions even though the PDF itself is exact.

Verify with a ruler
Print one test sheet on the intended paper and measure a known finished edge. Also confirm that the selected paper size and orientation match the loaded sheet.
PrintGrid Pro cannot control browser, driver, firmware, feed alignment, or borderless-printer behavior, so a physical sample remains the final check.