Added new kb article validating-fonts-document-processing

knowledge-base/validating-fonts-document-processing.md

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+---
+title: Checking and Validating Fonts for Telerik Document Processing
+description: Learn how to identify and resolve issues caused by incomplete or corrupt TTF font files in exported PDFs using Telerik Document Processing.
+type: how-to
+page_title: Resolving Missing Content Issues in PDF Export Due to Fonts
+meta_title: Resolving Missing Content Issues in PDF Export Due to Fonts
+slug: validating-fonts-document-processing
+tags: radwordsprocessing, document processing, ttf, font, validation, pdf export
+res_type: kb
+ticketid: 1690314
+---
+
+## Environment
+
+| Version | Product | Author | 
+| ---- | ---- | ---- | 
+| 2025.2.520| RadPdfProcessing |[Desislava Yordanova](https://www.telerik.com/blogs/author/desislava-yordanova)| 
+
+## Description
+
+When exporting a document to PDF using [Telerik RadWordsProcessing](https://docs.telerik.com/devtools/document-processing/libraries/radwordsprocessing/overview), missing content may occur due to issues with the TTF font file. These issues can arise if the font file is incomplete, corrupted, or missing required font tables. This results in missing or improperly rendered text in the exported PDF.
+
+This knowledge base article also answers the following questions:
+- Why does my PDF export have missing text due to fonts?
+- How can I validate fonts used in Telerik Document Processing?
+- What tools can check for font file integrity?  
+
+## Solution
+
+To ensure a font file is complete and compatible with Telerik Document Processing, follow these steps:
+
+1. **Open the Font in a Font Viewer**  
+   Double-click the TTF file to open it in the system font viewer. Inspect whether all expected characters display correctly and ensure no error messages appear.
+
+2. **Test the Font in Other Applications**  
+   Install the font on your system and use it in applications like Word or Notepad. Verify that all characters render correctly.
+
+3. **Compare File Size and Metadata**  
+   Compare the file size and properties of the font with an official or known-good version. Noticeable differences can indicate corruption or missing data.
+
+4. **Use Font Validation Tools**  
+   Validate the font file with tools like:
+   - [FontForge](https://fontforge.org/)  
+   - [Microsoft Font Validator](https://github.com/Microsoft/Font-Validator)  
+   These tools check for missing tables, corrupt glyphs, and other font-related issues.
+
+5. **Check Required Styles**  
+   Verify that all required styles (Regular, Bold, Italic, etc.) are available if your document uses them. Missing styles can cause fallback or rendering issues.
+
+### Recommendations
+
+- Validate fonts from third-party sources before integrating them.
+- Request official font packages or sources for reliable compatibility.
+- Replace problematic font files with known-good versions to resolve rendering issues.
+- Extend the FontsProvider to log missing or problematic fonts during testing for early detection.
+
+## See Also
+
+- [RadWordsProcessing Overview](https://docs.telerik.com/devtools/document-processing/libraries/radwordsprocessing/overview)  
+- [FontForge](https://fontforge.org/)  
+- [Microsoft Font Validator](https://github.com/Microsoft/Font-Validator)  
+- [Working with Fonts in Telerik Document Processing](https://docs.telerik.com/devtools/document-processing/fonts/fonts-overview)