To troubleshoot and fix OneNote printout quality issues, try the following steps:

1. Check that the OneNote file you’re trying to print from isn’t open in the OneNote Desktop App at the same time as Onenote Online in a browser.
2. Ensure the device you’re printing from has the latest version of OneNote and the latest Windows updates.
3. Verify that your printer is compatible with OneNote.
4. Ensure that you have the correct and up to date printer driver installed.
5. Change any Print Settings required for the particular printing job.
6. Run Printer Troubleshooter to detect any problems in the printer.
7. Check if the issue goes away while printing to PDF.
8. Perform a hard reset of your printer if the issue persists.