Every map starts with real geographic data from Overture Maps and OpenStreetMap - hundreds of millions of features stored in our PostGIS database and served as vector tiles. What you see in the preview is the actual road network, buildings, and waterways drawn in real time.
When you generate, a headless QGIS server renders a print-ready poster at up to 600 DPI. Post-processing injects vector masks and re-renders text as native SVG so every line stays razor-sharp at any size.