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Ref. Issue #9 - 06 June 2008 - Creating Your Own
Linetypes
AutoCAD and AutoCAD LT come with a large number of linetypes
and hatch patterns. However, when these do not serve your particular
needs, you can create your own linetypes and hatch patterns.
You can then use them in your drawings in the same way that you use
the linetypes and hatch patterns that come with the software.
Linetypes are useful whenever you don’t want a continuous linetype.
They apply not only to lines, but also to polylines, arcs, ellipses, wireframes,
and solids—in fact, to most objects. You use hatch patterns
to fill in closed (or almost closed) areas. Hatch patterns often represent
textures or materials.
Creating Linetypes
There are two types of linetypes: simple and complex. Simple linetypes
consist of only dashes and dots. Complex linetypes usually
have dashes and/or dots, but also contain text and/or shapes.
The default linetype file is acad.lin for AutoCAD and acadlt.lin
for AutoCAD LT. You can add your own linetype definitions to this file
or create your own linetype files. Linetype files are text files and must
have a .lin file extension. Of course, be sure to make a backup copy
of acad.lin or acadlt.lin before you edit it. You commonly use
Notepad to edit a linetype file.
Creating simple linetypes
In the syntax for creating simple linetypes, each linetype is defined
using two lines of text. The first line contains the linetype name and
an optional description, formatted as follows:
*linetype name[, description]
Here are some points to remember:
✦ Always start the definition with an asterisk.
✦ The description is limited to 47 characters.
✦ If you include a description, precede it with a comma.
The second line of the linetype syntax is its definition. With simple linetypes, you’re limited to
dashes, dots, and spaces, which are measured in units and specified as follows:
✦ A dash is indicated by a positive number.
✦ A dot is indicated by a 0.
✦ A space is indicated by a negative number.
✦ Each item is separated by a comma, there are no spaces, and the maximum line length
is 80 characters.
✦ Each line must start with the letter A.
The following definition creates a line with two dashes of 0.25 units, followed by two dots, all
separated by spaces of 0.1 units.
*seeingdouble, Future hedge line
A,.25,–.1,.25,–.1,0,–.1,0,–.1
If you feel quite confident, you can even create linetypes on the fly, using the command-line
form of the LINETYPE command. Type -linetype ↵ and use the Create option. Follow the
prompts and type the linetype definition on the command line. If you make a mistake, you
must open the linetype file in a text editor to make your corrections.
If your linetype definition will include both dashes and dots, you’ll get the best results when
you start the linetype definition with a dash. Starting the definition with a dash is a matter of
aesthetics, perhaps, but such a line connects better to other lines.
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