What medieval invention helped spread learning after the Middle Ages but began in Europe in the mid-15th century?

The story behind the answer

Developed in mid-15th century Europe, this technology combined movable metal type, oil-based inks, and a screw press to reproduce texts quickly and cheaply. Unlike hand-copied manuscripts, it slashed the time and cost of book production, vastly increasing access to learning and accelerating literacy after the medieval period.

Its first landmark product was the Gutenberg Bible (c. 1455), and within decades print shops spread across Europe, producing millions of volumes by 1500. The result was a communications revolution that helped ignite the Renaissance, fuel the Reformation, standardize languages, and speed the circulation of scientific ideas. By contrast, illuminated manuscripts were painstakingly handcrafted, the rotary press arrived in the 19th century, and a modern public library system developed much later.