Guust Ysebie Software engineer on the iText PDF SDK and member of the PDF Association, writing and speaking about PDF internals, standards, and performance. https://guust.ysebie.be/ 2026-04-19T00:00:00Z Guust Ysebie New EU Trusted Certificates Released https://guust.ysebie.be/blog/new-eu-trusted-certificates-updated/ 2026-04-19T00:00:00Z A blog post about the new EU Trusted Certificates that have been released and how to update LOTL validation feature with iText. Want to Make Your PDFs 20% Smaller for Free? https://guust.ysebie.be/blog/want-to-make-your-pdfs-20-smaller-for-free/ 2026-01-20T00:00:00Z Adding experimental Brotli compression to Pdf and iText Supporting org.apache.xml.security in GraalVM https://guust.ysebie.be/blog/supporting-apache-xml-security-algorithms/ 2025-08-13T00:00:00Z How to get org.apache.xml.security working in GraalVM native images. How I Made PDF Table Rendering 95% Faster in an Afternoon https://guust.ysebie.be/blog/how-i-made-pdf-table-rendering-faster/ 2025-05-16T00:00:00Z Improving PDF table rendering performance in the iText SDK.