24mo

With small dimensions of approximately 5" x 8" (127mm x 203mm), the 24mo format has a compact surface area around 40 square inches or 258 square cm. Also referred to as Twenty-Fourmo, this book size gets its name from 24 leaves of paper folded into one signature during old bookbinding practices. Larger than 32mo miniatures but smaller than Duodecimo sizes, 24mos became popular for portable pocket editions of literature and nonfiction. The petite 5" x 8" size allowed books to remain lightweight and easily carried, while having a bit more text per page compared to 32mos. Especially common in the 19th century for condensed travel books and children's stories, 24mos were ideal for keeping content accessible on-the-go. Originating from early printing press book formats, the 5" x 8" size could comfortably fit around 150-200 pages printed on both sides. While less common today, 24mo remains useful for specialized small books and pocket editions when minimal bulk is key. Its success stems from striking a balance of portability and formatting more text than tiny 32mo books.