Editing Technical drawing (section)

===Manual or by instrument===
[[File:Zeichenmaschine.jpg|thumb|left|A drafting table]]
[[File:Technical drawing instruments 1.jpg|thumb|right|Old-fashioned technical drawing instruments]]
[[File:Stencils01.jpg|thumb|right|Stencils for lettering technical drawings to DIN standards]]
The basic drafting procedure is to place a piece of paper (or other material) on a smooth surface with right-angle corners and straight sides—typically a [[drawing board]]. A sliding [[straightedge]] known as a [[T-square]] is then placed on one of the sides, allowing it to be slid across the side of the table, and over the surface of the paper.

"Parallel lines" can be drawn by moving the T-square and running a pencil or [[technical pen]] along the T-square's edge. The T-square is used to hold other devices such as [[set square]]s or triangles. In this case, the drafter places one or more triangles of known angles on the T-square — which is itself at right angles to the edge of the table — and can then draw lines at any chosen angle to others on the page. Modern drafting tables are equipped with a [[drafting machine]] that is supported on both sides of the table to slide over a large piece of paper. Because it is secured on both sides, lines drawn along the edge are guaranteed to be parallel.<ref>{{cite book|last=Bhatt|first=N.D|title=Machine Drawing|publisher=Charotar Publication}}</ref>

The drafter uses several [[technical drawing tools]] to draw curves and circles. Primary among these are the [[Compass (drafting)|compasses]], used for drawing arcs and circles, and the [[French curve]], for drawing curves. A [[Flat spline|spline]] is a rubber coated articulated metal that can be manually bent to most curves.

Drafting templates assist the drafter with creating recurring objects in a drawing without having to reproduce the object from scratch every time. This is especially useful when using common symbols; i.e. in the context of [[stagecraft]], a lighting designer will draw from the [[USITT]] standard library of lighting fixture symbols to indicate the position of a common fixture across multiple positions. Templates are sold commercially by a number of vendors, usually customized to a specific task, but it is also not uncommon for a drafter to create his own templates.

This basic drafting system requires an accurate table and constant attention to the positioning of the tools. A common error is to allow the triangles to push the top of the T-square down slightly, thereby throwing off all angles. Even tasks as simple as drawing two angled lines meeting at a point require a number of moves of the T-square and triangles, and in general, drafting can be a time-consuming process.

A solution to these problems was the introduction of the mechanical "drafting machine", an application of the [[pantograph]] (sometimes referred to incorrectly as a "pentagraph" in these situations) which allowed the drafter to have an accurate right angle at any point on the page quickly. These machines often included the ability to change the angle, hence removing the need for the triangles.

In addition to the mastery of the mechanics of drawing lines, arcs and circles (and text) onto a piece of paper—with respect to the detailing of physical objects—the drafting effort requires a thorough understanding of geometry, [[trigonometry]] and spatial comprehension, and in all cases demands precision and accuracy, and attention to detail of high order.

Although drafting is sometimes accomplished by a project engineer, architect, or shop personnel (such as a [[machinist]]), skilled drafters (or designers) usually accomplish the task, and are always in demand to some degree.