This talk introduces a comparative component to the Newberry's theme of Religious Change, 1450-1700. From 1450-1700, European society experienced drastic changes in practices of religion, communication, and book production. Concurrently, Islamic society experienced drastic changes of its own, bookended by the Ottoman conquest of Constantinople (Istanbul) in 1453 and the opening of the first officially-sanctioned Ottoman printing press in 1726. Drawing upon my recent book, Letters of Light: Arabic Script in Calligraphy, Print, and Digital Design, this talk compares the European and Ottoman trajectories. Although European printers began setting moveable Arabic type in the sixteenth century, Ottomans did not adopt printing presses for their own purposes until the eighteenth century. The two and a half centuries that separate Gutenberg and Ibrahim Müteferrika, the first Ottoman printer, continues to baffle historians, but the apparent "delay" in Ottoman printing may not be as drastic as often suggested. The Latin alphabet and Arabic script followed very different trajectories from handwritten page to printed book. This talk explores some of the cultural and technological reasons for those differences.