AutoCAD As an Illustration Tool
by Ron Adee, CADdigest.com
Electronic media is being shared and exchanged by a wide variety
of clients, contractors, architects and engineers. Microsoft has
made much of this collaboration possible through its operating
systems and software. It is no problem to exchange files
generated from a Microsoft Office Suite program (i.e. Word,
Excel, Access, PowerPoint). But what happens when you want to
share an AutoCAD drawing with a non-AutoCAD user?
AutoCAD has tried to address this need by providing free drawing
viewers such as Volo View and Whip! But even these programs are
too cumbersome and confusing for the average office worker. A
need exists to be able to translate an AutoCAD drawing that is
immediately viewable and understandable to the least computer
In this article I will try to address AutoCAD’s limitations and
some solutions I have found using two of the most widely used
graphic viewers in use today, PowerPoint and Adobe. But first
CAD vs. Image Editors
AutoCAD is a powerful CAD drafting program that has been around
since 1982. It is the world's most popular CAD program,
accounting for 70% of CAD sales since its inception. It is a
good generic CAD program. By generic I mean that the program can
draw all of the basic geometric shapes such as lines, text,
arcs, circles, etc. By generic I also mean that it can be
adapted to a wide variety of uses. For instance, it can and has
been used for machine design, and for countless architectural,
structural, civil, electrical and mechanical projects. It does
what all CAD programs do: draw objects with extreme precision
What AutoCAD does not do very well is image editing --
that is, tasks such as freehand artwork, or shading, rendering
and annotating. Programs designed for image editing and as
publishing aids have been available for years; there are
distinct differences between these image editor programs and CAD
AutoCAD, for example, was designed with the ultimate goal of
sending the finished result (a drawing) to a plotter. Great care
was taken in programming AutoCAD to enable a user to plot a
drawing with various line weights and at different scales and
sizes. You might say that, in a sense, AutoCAD is plotter
Image editor programs, on the other hand, were designed with the
goal of sending the finished result to a lithographer. In other
words, the finished product has to look good when printed.
Therefore, image editor programs could be considered printer
An AutoCAD drawing does not look so good on a screen. This is
because the lines are vector lines, which have no width. This
goes back to the days of pen plotters when vector lines were
used to give distance and direction information to a plotter
Image editor lines look good on a screen because they are raster
lines. Raster lines are composed of a series of “dots.” Raster
images are not meant to be sent to a plotter, but to a camera. A
camera in the hands of a lithographer will take a picture of the
image and transfer that image to a plate. This image will
contain hundreds of dots.
With the advent of the Internet, AutoCAD and other CAD programs
have made great strides in incorporating raster images into
their software. Image editor programs have likewise made great
strides in incorporating vector images into their products.
However, neither one can totally replace the other.
In general, CAD programs are best for doing straight,
rectilinear lines and for crisp clean angles and corners. Image
editor programs are best suited for images with gradual changes
in texture, color, shape and shade. To put it in other terms,
CAD drawings are cartoon-like while image editor drawings are
more like photographs.
PDF or PowerPoint
PDF, which stands for Portable Document Format, is the file
format produced by programs such as Adobe Illustrator and
Photoshop. I installed Photoshop on my computer when I was
testing out a scanner. Even after I uninstalled the software, I
was left with a plug-in program called PDF Writer. This program
installs a "virtual" printer and also installs a new command
line in all Microsoft products called Create Adobe PDF, which
directs output to the PDF Writer. This in turn translates all
Microsoft information into a PDF file that is readable by
Since PDF Writer also installs a virtual printer, it is possible
to use it to convert other types of documents, inlcuding AutoCAD
drawings. First, you have to configure a Windows System Printer
in AutoCAD. To do this, go to Settings, Printers and make the
PDF Writer the Default printer, then (in AutoCAD) go to Tools,
Preferences (Options) and add a New Printer. Pick the System
Printer option and answer all defaults.
A word of caution: in AutoCAD 2000 there is a bug when
doing a full preview to the PDF Writer. This is documented in
the AutoCAD “known limitations” file. Doing a full preview will
cause AutoCAD 2000 to fatal error.
Sending an AutoCAD drawing to PDF Writer has several advantages:
You can use the AutoCAD pen assignments and widths
You don’t have to change the background color to white
You can plot paperspace viewports as well as modelspace
PowerPoint is installed on many office computers that come with
the Microsoft Office Suite. I have used PowerPoint many times
for distributing AutoCAD drawing information to non-AutoCAD
users. It has proven effective, but has several drawbacks. You
widen the lines of the AutoCAD drawing
change all fonts to a bold Truetype font
change the background color of the drawing to white
minimize the drawing window to be the approximate size of the
export a .wmf file from AutoCAD and paste this into a blank
There are also advantages to using PowerPoint. You can:
crop or enlarge the graphic and other add other elements such as
arrows, bullets, and text
project the graphic onto an overhead screen
build a slide show
The advantages of PDF include its ability to:
distribute drawings to contractors or others who don’t have
easily and quickly create a multiple pen width drawing in
create a drawing that is not editable and therefore “secure”
For those without access to PDF Writer, there are other free
alternatives. One is a program called PDF995, available as a
download. I have used it and it is very versatile. The free
version has banner ads that pop up each time the program is
launched, but these can be disabled for the cost of $9.95 (hence
the 995 in PDF995). Here is a link to their site: <http://www.pdf995.com>.
And here is a link to another PDF site: <http://www.jwwalker.com/pages/pdf.html>.
Some things to consider when preparing AutoCAD for graphic
Before I export a .wmf file, I always make the background of my
drawing white. To do this, go to Tools, Preferences (Options),
and Display. Choose Colors and the “Graphic windows background.”
Then select white from the basic colors palette. Then click OK
and Apply. This is not necessary for .pdf files, because the
drawing is sent to the PDF Writer as a Postscript file.
Postscript ignores background color.
But the color of the vector lines and text is important. Most
AutoCAD users are accustomed to working with a black background.
Foreground colors like yellow, magenta and cyan contrast well
with a black background but not with a white one.
Another consideration is the printed color. Most modern
monochrome printers apply a grayscale equivalent to certain
colors. For instance, red will be printed as a dark gray color
and blue will be printed pure black. Yellow, on the other hand,
will be printed as a light gray.
When preparing for a presentation I make a separate drawing. I
then revise my colors on that drawing to a more practical
palette. How do I determine what colors go on this palette?
First, I choose what looks good on the screen. Colors that
offers the best contrast on a white background are red, blue,
green and white (which converts to black when the background
color is changed). I sometimes use colors such as cyan and
magenta for hatch patterns and fills.
Next, I find the best contrast between these colors on a
monochrome print. To do this, take the AutoCAD “chroma” or
“colorwh” drawing (found in the Support folder) and make a print
of it. This will give you an idea of the grayscale shading that
occurs in every AutoCAD color. Below is an example (click
image to enlarge)
It can be a challenge sometimes to find a color that looks good
on both a screen and a print. After some practice, you will
develop an “eye” for the saturation of a particular color and
how dark it will print.
For more information, see my article, “Raster Images,” which can
be found in my Adee’s AutoCAD Answers website archive. See my
About the Author
Ron Adee is a senior engineering technician who works for the
Kansas Air National Guard in Topeka, Kansas. He began drafting
in 1975, started using CAD full time in 1983 and has been using
AutoCAD since 1991.