| The basic mechanics
of drafting is to place a piece of paper (or other material) on
a smooth surface with right-angle corners and straight sides - typically
a drafting table. 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
simply by moving the t-square and running a pencil or technical
pen along the t-square's edge, but more typically the t-square is
used as a tool to hold other devices such as set squares or triangles.
In this case the draftsman 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 come equipped with
a parallel rule 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.
A pair of compassesIn addition,
the draftsperson uses several tools to draw curves and circles.
Primary among these are the compasses, used for drawing simple arcs
and circles, and the French curve, typically a piece of plastic
with complex curves on it. A spline is a rubber coated articulated
metal that can be manually bent to most curves.
Drafting templates assist the draftsperson
consistently recreate 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 typically 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 draftsperson to create their own templates.
|