turn

In metal type composition, a turn was an emergency substitution: when a printer ran short of a particular character or font, they would physically invert (flip upside down) a piece of type of matching thickness and use it in place of the missing sort. This worked only when the upside-down character bore some visual resemblance to the needed letter, or when the substitution was acceptable enough to readers. The practice was born from economic necessity and the high cost of casting complete font sets.

The technique relied on type being cast to uniform thickness (or height-to-paper), so that inverted sorts would lock into the forme at the correct printing level. A turned lowercase 'b' might serve as a 'd' in a pinch; a turned '6' could stand in for a '9'. This only worked with characters that had rotational symmetry or near-symmetry. Printers would mark their chase or forme to track which characters had been turned, so the compositor could restore correct type during redistribution.

Turning was most common in job printing shops with limited capital, where buying replacements for every exhausted sort was impractical. Large printing houses with extensive type foundries and deep stocks rarely needed to resort to turning. The practice declined as type founding became more efficient and competitive in the 19th century, and it became obsolete after phototypesetting and digital composition eliminated metal type altogether.

The term appears dated in modern printing contexts because it describes a problem that no longer exists. Contemporary compositors and typesetters do not encounter exhausted type, and the word survives mainly in historical accounts of hand composition and in the vocabulary of letterpress revival. However, the term remains useful for understanding the constraints and workarounds of historical print shops, where material scarcity often shaped production decisions.