Offline, book-focused generator — nothing is uploaded or sent anywhere.
Transparent output: only use it when the entire barcode area, including the quiet zones, will sit over solid white. A photograph, texture, colour or gradient behind the barcode can reduce scan reliability.
Print default: at 100% the finished symbol is 37.29 × 25.93 mm, including the required quiet zones and human-readable digits. SVG is the preferred master for a book cover because the bars remain vector-sharp.