Double great primer is a historic letterpress type size that measures exactly 36 points. As the name suggests, it equals the height of two lines of 18-point great primer type. Printers relied on this substantial size for prominent display work, posters, and major chapter headings before the universal adoption of the numerical point system.
Heard on the job
Pull the 36-point spacing material if you're locking up that double great primer headline.
Insider tip
At exactly half an inch tall, this size remains a standard benchmark in layout, though the traditional name is rarely used outside of letterpress shops.