How to Preserve Text Layers When Converting CAD to PDF
Question details
The user wants to ensure that text remains selectable and searchable when exporting or converting a CAD drawing into a PDF file.
- Product
- CAD Software, PDF Editors
- Device & OS
- not provided
- Scenario
- Converting CAD drawings to PDF format for sharing and archiving while maintaining text searchability.
- Observed behavior
- Exported PDFs often convert text into vector graphics or images, preventing OCR software or users from selecting and searching the text.
Check the font types used in your original CAD file. TrueType fonts (TTF) are generally required for text to remain searchable, whereas SHX fonts often get converted into unsearchable line graphics.
Configure CAD Software Export Settings
The most effective way to preserve text is configuring your CAD software to export TrueType fonts as searchable text rather than vector graphics.
Standard PDF editors cannot magically reconstruct a text layer if the CAD program originally exported the text as vector paths. The conversion must be handled correctly at the source application.
Open your drawing in your CAD software and ensure that the text styles use TrueType fonts (e.g., Arial, Times New Roman) rather than SHX fonts.
Select the built-in 'DWG to PDF.pc3' plotter or navigate to the 'Export to PDF' function. Open the 'PDF Options' dialog.
Ensure that the 'Capture fonts used in the drawing' or 'Include searchable text' option is checked before finalizing the PDF export.
Perform OCR on the Exported PDF
If you only have access to the flattened PDF and cannot re-export from the original CAD file, use Optical Character Recognition (OCR) to extract the text.
Extract Text from CAD PDFs with WPS Office OCR
If your CAD software exported text as unselectable graphics, you can use the advanced OCR feature in WPS Office to recognize and extract text from your PDF drawings easily.
- 1. Open the Flattened PDF: Launch WPS Office and open your CAD-generated PDF file.
- 2. Access the OCR Tool: Go to the 'Tools' tab on the top ribbon and click on the 'OCR' button.
- 3. Extract Text: Choose 'Extract Text' or 'Convert to Word', select the document language, and click 'Start' to convert the graphical text into searchable characters.
Frequently Asked Questions
Why does my CAD text turn into lines in PDF?
Many CAD programs use specialized SHX fonts optimized for drafting. When exported to PDF, these fonts are often drawn as vector lines rather than embedded as standard TrueType text fonts, making them unselectable.
Can Adobe Acrobat convert CAD lines back into text automatically?
Adobe Acrobat alone cannot recreate the original text layer if the text was exported as vector paths. You must either export the file properly from the CAD software or manually run an OCR tool to recognize the vector lines as text.
Does the EPDFSHX command fix all text search issues?
Setting the EPDFSHX system variable to 1 in AutoCAD helps make SHX fonts searchable by adding hidden text over the geometry in the PDF. However, using TrueType fonts provides the most reliable and universally selectable text layer across all PDF viewers.
