[reportlab-users] Issues related to setting parameters of graphs, lines, and rectangles, and they are not printing correctly

[Tim Roberts]

J. R. Carroll wrote:

>

> The next problem:  now we have to find a balance between "what looks

> good on the screen" and "what looks good on print" (in both grayscale

> and color).


I'm not sure you really grasp what an incredible swamp you have wandered
into.  Watch out for rodents of unusual size.

When you say "what looks good on the screen", do you mean "as displayed
by whatever PDF reader application you happen to be using, on whatever
monitor you happen to be using, at whatever color temperature it happens
to use, at whatever brightness the monitor is set, at whatever gamma
value it has, with whatever ambient light happens to be present"?

Color matching is quite literally a science into itself, and it is a
complicated science at that.  The number of variables is virtually
infinite.  Besides the variability in monitors (and there are
calibrators to help with that) and ambient light, different PDF reader
applications interpret the Postscript instructions in different ways. 
MacOS tries to do sophisticated color matching adjustments based on the
monitor attributes.  Windows has that ability, but the application has
to request it.

As long as you define your goals clearly, you can achieve good results. 
But you will never, for example, be able to create a PDF that looks the
same on the screen as it does on an arbitrary printer.  It's just not
possible.

-- 
Tim Roberts, timr at probo.com
Providenza & Boekelheide, Inc.