Color prints from O/FRODO

Ethan A Merritt merritt at
Thu Apr 15 12:01:19 EST 1993

In article <1qj893$e8p at> schlaude at (Gerd Schlauderer) writes:
>In our lab we take a photograph of the screen if we need a colorpicture
>for a publication. The whole procedure takes some time and you have
>to wait at least one day to see if the results are satisfying.
>Is there a possibility to produce screen dumps on a color printer or
>postscript files. And what is the quality of such prints. Anything less
>than 300dpi is not enough for publication.


A number of programs produce PostScript output, including
MOLSCRIPT	cf: Per Kraulis, J. Appl. Cryst. (1991) 24:946.
FRODO (CCP)	"plot" command followed by PostScript translation program
O		"plot" command followed by O_PLOTAT program
		(but beware that the various versions are not compatible)

You can get good results from these using fairly inexpensive color printers,
either pen plotters like the HP 74xx series or inkjet dot-matrix printers.
I have gotten nice density+atom plots from O/O_PLOTAT, but only by 
modifying the PostScript output file to correct scaling errors, line
widths, and color specifications.


For raster pictures, including ray-tracing graphics at the top end and
simple screen dumps at the bottom end, the situation is different. The
critical step here is usually conversion to a file format understandable
by the printer.  For general conversion to/from various raster formats
there are a number of freely available packages, including:

ImageMagick	John Cristy		various ftp sites
pbmplus		Jeff Pozkasner (sp?)	various ftp sites
San Diego Supercomputer Image Tools 	(Email to info at

Up until recently the only real options here were photography from the
screen or the use of a film recorder (hard to find and very expensive).
The simple (ink jet, pen, thermal wax) printers available previously
were useless for this kind of picture.  There is now a new kind of
printer called a "dye sublimation printer", however.  I have no idea how
it works, but the picture quality is fantastic!  Since the medical
illustration service here got one (made by a company called Rasterops)
it has completely changed the way I generate hardcopy of this sort of
picture.  I can preview the pictures using the laser printer here at the
lab, and then send the same file to the Rasterops printer to get a copy
in 300dpi glorious color with much better quality then I (no great
photographer) have ever managed from the screen.  I think the printer is
more expensive than one would want for a single lab, but maybe you could
persuade the computer center or photography/illustration service center
or whatever to get one on a pay-per-sheet basis as we have here.

					Ethan A Merritt
Dept of Biological Structure            H510 Health Sciences
University of Washington SM-20          (206)543-1421
Seattle, WA 98195                       merritt at

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