Editing Engineering drawing (section)

=== Technical lettering ===
[[Technical lettering]] is the process of forming letters, numerals, and other [[character (computing)|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 lettering ability has little relationship to normal writing ability. Engineering drawings use a [[sans-serif|Gothic sans-serif]] script, formed by a series of short strokes. Lower case letters are rare in most drawings of [[machine]]s. ISO Lettering templates, designed for use with technical pens and pencils, and to suit ISO paper sizes, produce lettering characters to an international standard.  The stroke thickness is related to the character height (for example, 2.5&nbsp;mm high characters would have a stroke thickness - pen nib size - of 0.25&nbsp;mm, 3.5 would use a 0.35&nbsp;mm pen and so forth). The ISO character set (font) has a seriffed one, a barred seven, an [[open four]], six, and nine, and a round topped three, that improves legibility when, for example, an A0 drawing has been reduced to A1 or even A3 (and perhaps enlarged back or reproduced/faxed/ microfilmed &c). When CAD drawings became more popular, especially using US software, such as AutoCAD, the nearest font to this ISO standard font was Romantic Simplex (RomanS) - a proprietary shx font) with a manually adjusted width factor (override) to make it look as near to the ISO lettering for the drawing board. However, with the closed four, and arced six and nine, romans.shx typeface could be difficult to read in reductions. In more recent revisions of software packages, the [[TrueType]] font ISOCPEUR reliably reproduces the original drawing board lettering stencil style, however, many drawings have switched to the ubiquitous Arial.ttf.