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We're happy to print Powerpoint
documents but the following article is worth reading first to avoid
disappointment.
NOTE: This article by
Andrew Hardwick refers specifically to poster printing - however the advice
given applies to most high quality commercial print.
Overview
Microsoft
Powerpoint has, regrettably, not only become the default program for doing
presentations is probably also the most common program for making posters
(with the possible exception of Microsoft Word which is even less suited to
the task). Also regrettably both academic & business posters are, these
days, usually judged more on flashy appearance than on content. These two
requirements are not very compatible because Powerpoint was only really
designed for bullet point presentations. Even if one is used to producing
on-screen presentations in Powerpoint, different tricks are needed for
overcoming Powerpoint's faults when printing.
Of course,
professional artists & graphic designers have far better programs for
drawing, typesetting and rendering posters. If you are one of those then stop
reading this and stick with those programs. Unfortunately the rest of us get
stuck with Powerpoint, either because it is the only vaguely suitable
program which comes bundled with most office computers, because it is
corporate policy to use it or because one has been given a template or
background in Powerpoint format. When I first tried producing a high quality
conference posterboard in Powerpoint, I found numerous problems. The
following is based on tricks I found to get around them. This is an addendum
to my previous article "How
to do Powerpoint Animations" (more info at the bottom of the page). That article is more comprehensive
and covers, as well as animations, advice on basic Powerpoint use and adding
graphics. Those bits should be read before reading this unless you are
already familiar with the tricks for producing tidy on-screen graphics in
Powerpoint.
In the following I
am referring to the 2000 version of Powerpoint (the 97 version was probably
similar but any versions before that are inadequate for image importing) for
M$ Windows (I expect other platform versions will be similar except that
commands might be in different menus). Later versions will probably have the
same features plus some more but, even so, it is good practice to only use
the oldest set of features that do the job because (a) those are most likely
to have been debugged, and (b) the presentation should still work when saved
as an older file type lest you have to use it on a system older than your
own.
Why Posters Differ
from On-screen Presentations
When making
posters, different tricks are needed get around the deficiencies of
Powerpoint from those needed for on-screen presentations. Some things are
much easier. For example, there is no worry about whether animations will
work or not in the live show; once a poster is printed, it is complete and
safe from further Powerpoint bugs. Neither does it need to work on other
people's computers (although if it does so then it is more likely you will
be able to edit & reuse parts of the poster on your own future
computers).
However there is
one big snag: the resolution required is much higher. A typical computer
projector screen is only 1024 dots across whereas even a 1 metre wide poster
at typical 600 dpi printer resolution is about 24 000 dots across. The
picture quality needs to be much better to avoid looking scruffy, especially
if people can get close to it.
Bitmapped Images
For photographic
and other bitmapped images the solution is conceptually simple - just use
higher resolution copies. This inevitably increases the overall file size
but that is not so much of a problem as for on-screen presentations because
you only need to ship the print-out eventually, not the original file. Even
if you are using an external print-shop to produce your posters, they are
used to artists with little underlying computer conceptualization sending
them absurdly huge files so, as long as you have a fast network connection
or a CD-writer then this is not much of a problem. Even so it is best to
experiment with different resolutions and compression methods to prevent the
file being unnecessarily large (e.g. an image that works on-screen with a 15 Kb
file might need a 200 Kb file for printing but probably not a 30 Mb
one as I've had one artist send me) as it may cause the programs and
printers may run annoyingly slowly.
A more serious
problem is that requires one to have the original images in high resolution
in the first place. You may have to go out photographing or rendering again
if you did not keep (or make) high resolution originals
Vector Images
Vector images are
ideal for posters because they can be blown up to any size and printed at
full printer resolution giving impressively sharp lines & clean solid
colours with no redrawing effort and no increase in file size.
Unfortunately, the
vector drawing facilities in Powerpoint itself are very primitive and
importing pictures from better vector drawing programs, like Corel Draw,
Adobe Illustrator or Macromedia Freehand, into Powerpoint without converting
them into bitmaps (which would loose the ability to enlarge them neatly)
does not work well. Powerpoint treats them as embedded editable objects,
which cause problems if they are then transferred to a computer without that
particular editing program. It also uses a bitmap copy of the images for
display anyway, which does not rescale well and vastly increases the file
size.
One solution is to
use EPS as an intermediary image format. EPS, Encapsulated Postscript, is a
version of the Postscript printer command language adapted for use with
individual images rather than whole documents. Most good vector drawing
programs should be able to export directly to EPS retaining the image in a
vector form (if yours does not then you can still produce EPS in a manner
similar to how one can produce
PDF files). EPS images can be included in Powerpoint in the same way as
normal JPEG & PNG images whilst retaining the vector ability to expand
to any size at full resolution when printed.
As expected with
Powerpoint, its EPS implementation is faulty. In particular, it cannot
render EPS on-screen, only when printing to a Postscript printer, so an EPS
image is not good for on-screen presentations. Powerpoint only uses the
preview bitmap version of the image that is embedded in the EPS file. The
preview image is not normally compressed well and, of course, does not
rescale well. The embedding of a preview in EPS is optional so, if you do
not mind not seeing the image on-screen whilst editing in Powerpoint, you
can make the file much smaller by missing it out entirely. I personally used
a compromise of a very low resolution embedded preview image to remind me
what it the image was.
That EPS fault in
Powerpoint unfortunately implies that separate versions of the Powerpoint
presentation need to be made for printing & on-screen display if one
wants both looking smart.
Printing
Remember that it
needs a Postscript printer for Powerpoint to correctly print EPS as
Powerpoint cannot render EPS itself. If printed on a non-Postscript printer,
the images will be the scruffy preview ones or completely missing. To avoid
this problem, take the whole presentation/posterboard and convert
it into Postscript or PDF before printing. This will also allow you to
print it from a computer without Powerpoint installed and makes it safer
when sending for someone else to print as it avoids the risk of their
version of Powerpoint rendering it differently.
Print a test sheet
first to check the colour rendition on the printer is how you expected (or
better) and adjust the settings in the printer drivers if the colours come
out wrong. Remember that the colour capabilities of ink are not the same as
a computer monitor. The monitor can do real real glowing colours which the
printer, using reflected light, cannot but ink can give a much fuller colour
range, in particular in the depths of dark colours, giving possibilities of
a richer & more realistic appearance. Choose your poster & on-screen
colour schemes accordingly.
One also needs to
choose how to mount the poster and what shape to make it. The most popular
mounts are:
-
Just paper:
Cheap for mass production but looks amateurish for a feature posterboard
and is very easily damaged (especially if an ink-jet printer, rather
than a laser printer, was used as the ink from it is very
water-soluble).
-
Paper stuck
on foam-board: This is easy to make, stands out from the wall and
used to be fashionable but the stiff board is very cumbersome to carry
(and it still needs protection from water spills if it was from an
ink-jet).
-
Plasticised
paper: Looks good, easy to carry and is reasonably durable other
than from creasing but expensive.
-
Plastic
laminated covering : Looks good, is easy to carry and is very
durable but expensive (unless one can have it done at trade prices).
The shape of the
poster is a risk unless is sure in advance what size the space is. If one
brings a short wide poster and finds that the display stand is tall and thin
then fitting it is going to be rather difficult and/or ugly. A work-around
is to make the posterboard out of several separate smaller sheets which can
be arranged as needed. This also has the advantage that one can fit it in
one's rucksack or suitcase rather having to carry a large awkward separate
document tube or folder.
Aspect Ratio
Yet another catch
is that Powerpoint, by default, prints at screen aspect ratio & with a
thick white border. To remove these two unwanted features, change the paper
size in Page Setup to the one with the same aspect ratio as the printer
paper and set it to "scale to fit" the paper in the printing
dialogue box respectively. Both these options are (of course!) badly
implemented in Powerpoint. Changing the aspect ratio causes Powerpoint to
attempt to squish the background images in the Slide Master to match, which
typically looks a mess so one has to delete the corrupted background
artwork, copy the original back in from an unaltered copy of the Powerpoint
file and then manually adjust it to fit. As for the scaling to fit printer
paper setting, this setting is often forgotten by Powerpoint so remember to
check it is still set each time before printing.
By
Andrew Hardwick.
Distributable under GPL freeware licence.
First version written 2002/11/5.
Converted to HTML 2003/3/1.
Available on-line at http://duramecho.com/. |
