Set the DPI

DPI (dots per inch) determines how many individual ink dots the printer places within each inch of paper. Raising the Dpi property on PrintSettings increases the sharpness of text, images, and fine lines - 300 DPI is a common choice for professional-quality documents.

Keep in mind that the actual resolution is capped by the printer hardware. If you request 600 DPI on a printer that tops out at 300, the driver will use its maximum capability. Higher DPI values also increase spooler file sizes and print times, so choose a resolution that balances quality with throughput for your specific use case.