Engineering drawing drawing on A3 may be enlarged to A2 or reduced to A4. The U.S. customary "A-size" corresponds to "letter" size, and "B-size" corresponds to "ledger" or "tabloid" size. There were also once British paper sizes, which went by names rather than alphanumeric designations. American Society of Mechanical Engineers (ASME) ANSI/ASME Y14.1, Y14.2, Y14.3, and Y14.5 are commonly referenced standards in the U.S. Technical lettering is the process of forming letters, numerals, and other characters in technical drawing. It is used to describe, or provide detailed specifications for an object. With the goals of legibility and uniformity, styles are standardized and
Ledger line claim that the word originates from the French "léger", meaning "light" or "slight" . The Oxford online dictionary describes the origin of the "leger" spelling as a "variant of ledger" that first appeared in the 19th century . Although ledger lines are found occasionally in manuscripts of plainchant and early polyphony, it was only in the early 16th century in keyboard music that their use became at all extensive . Even then, printers had an aversion to ledger lines which caused difficulties in setting type, wasting space on the page and causing a messy appearance. Vocal music employed a variety