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
Paper size below. "Letter, Legal" and "Ledger/Tabloid" are by far the most commonly used of these for everyday activities, and the only ones included in Cascading Style Sheets (CSS). The origins of the exact dimensions of Letter size paper () are lost in tradition and not well documented. The American Forest and Paper Association argues that the dimension originates from the days of manual paper making, and that the 11-inch length of the page is about a quarter of "the average maximum stretch of an experienced vatman's arms." However, this does not explain the width or aspect ratio. Outside of North America,