Medieval letter tile

They were created by pressing stamps bearing a reverse image into soft clay, which was then baked hard, and they were used to form words by assembling single-letter tiles in the desired order.

[1] The decoration technique is notable for being an early form of movable type printing which essentially is nothing but the stringing together of identically created individual letters for the purpose of producing an image.

[2][3] Compared to the conventional printing technique later established by Johannes Gutenberg, though, medieval tile alphabets were created in an inverse order: In a first step, the (im)printing was done, and only then the process of typesetting occurred, by spreading out the individual letter tiles onto the floor and composing them into words and lines of text.

[6] In Zinna Abbey south of Berlin, there is an extant Ave Maria embedded in the floor before the altar.

Each letter appears as a relief print on an unglazed, red-brown terracotta tile measuring 14 x 14 cm.