How to Fix Uneven Underline Thickness in PDF Files
Question details
The user needs to resolve an issue where underlines in a PDF document appear to have varying thicknesses when viewed on a screen.
- Product
- Adobe Acrobat / Microsoft Word
- Device & OS
- not provided
- Scenario
- Viewing a PDF file that was recently converted from a Microsoft Word document.
- Observed behavior
- Underlines that are identical in the source Word document display with uneven or varying thicknesses in the PDF viewer.
Verify that the underlines are indeed uniform in the original Microsoft Word document and ensure your PDF reader is updated to the latest version.
Disable the Enhance Thin Lines Setting in Adobe Reader
Adjusting the page display preferences in Adobe Reader will fix the visual rendering of thin lines on your monitor without altering the actual file data.
Adobe Reader and Acrobat use a setting designed to make thin lines more visible on computer screens. While helpful for some technical drawings, this feature often artificially thickens standard text underlines, causing them to appear uneven.
Launch Adobe Acrobat or Reader. Go to the 'Edit' menu at the top and select 'Preferences' (or press Ctrl+K).
In the Preferences dialog box, select the 'Page Display' category from the left-hand navigation pane.
Look for the 'Rendering' section. Uncheck the box labeled 'Enhance thin lines', then click 'OK' to save your changes.
Try Alternative PDF Conversion Methods in Word
If adjusting the display settings does not resolve the problem, changing the method used to export the PDF from Word can produce better line rendering.
Use WPS Office for Consistent PDF Formatting
WPS Office features a robust built-in PDF converter and native viewer that ensures exact formatting retention from Word documents, easily preventing visual rendering issues like uneven underlines.
- 1. Open your document: Launch WPS Writer and open your original word processing document.
- 2. Export to PDF: Click on 'Menu' in the top-left corner, go to 'Export to PDF', and configure your desired export options.
- 3. View without errors: Open the newly generated PDF directly in WPS PDF. Your underlines and formatting will render cleanly and evenly.
Frequently Asked Questions
Why do underlines look thicker on some pages of my PDF but not others?
This is typically a display rendering quirk caused by the 'Enhance thin lines' feature in Adobe Acrobat or Reader. The software artificially thickens lines based on zoom levels and screen resolution to make them more visible, which can result in inconsistencies from page to page.
Will uneven underlines in a PDF show up when printed on paper?
Usually, no. The uneven thickness is almost always a screen rendering artifact. When sent to a high-resolution physical printer, the document will typically print with uniform underline thicknesses just like the original Word file.
Does the method used to convert Word to PDF affect line thickness?
Yes, different conversion processes handle vector graphics and text rendering differently. Using the 'Save As PDF' built-in function versus using an external 'Print to PDF' driver can sometimes affect how structural lines are drawn and rendered in the final PDF file.
