Postscript printer CMYK alignment page available

[David Mathog]

I wrote a postscript CMYK alignment page and thought somebody else might
also find it useful. If so, come and get it:

ftp://saf.bio.caltech.edu/pub/software/linux_or_unix_tools/test_color_printer.ps

The test assumes an 8.5" x 11" page and emits a black rectangle 0.5" in
from all margins. Use a ruler and this rectangle to adjust the
printer's K vertical and horizontal offsets to place the K image
exactly where it should be on the page. The method for making these
adjustments will vary by printer.

The test page also prints clusters of black lines
and then writes colored clusters (with one less line]
than before) in Cyan, Magenta, and Yellow _over_ the black lines.
(Picture a bar code with three colored stripes across it.) There
are two such alignment clusters: vertical and horizontal. When
CMY are properly aligned to K on the test printer the end
lines in each cluster will have their respective colors
perfectly lined up with the black lines underneath them.
I found that it was easier to see color offsets, especially for
yellow, in this format than in the original calibration page
provided by the printer.

Here are some keyword phrases to aid retrieval of this message
using search tools:

postscript color alignment page
printer color alignment page
CMYK alignment page
align colors
align CMYK

Regards,

David Mathog
(e-mail address removed)

 

[Gernot Hoffmann]

I wrote a postscript CMYK alignment page and thought somebody else might
also find it useful. If so, come and get it:

ftp://saf.bio.caltech.edu/pub/software/linux_or_unix_tools/test_color_printer.ps

The test assumes an 8.5" x 11" page and emits a black rectangle 0.5" in
from all margins. Use a ruler and this rectangle to adjust the
printer's K vertical and horizontal offsets to place the K image
exactly where it should be on the page. The method for making these
adjustments will vary by printer.

The test page also prints clusters of black lines
and then writes colored clusters (with one less line]
than before) in Cyan, Magenta, and Yellow _over_ the black lines.
(Picture a bar code with three colored stripes across it.) There
are two such alignment clusters: vertical and horizontal. When
CMY are properly aligned to K on the test printer the end
lines in each cluster will have their respective colors
perfectly lined up with the black lines underneath them.
I found that it was easier to see color offsets, especially for
yellow, in this format than in the original calibration page
provided by the printer.

Here are some keyword phrases to aid retrieval of this message
using search tools:

postscript color alignment page
printer color alignment page
CMYK alignment page
align colors
align CMYK

Regards,

David Mathog
(e-mail address removed)

David,

thanks for your contribution. In the moment I can´t see how the
correction for the printer could be done straightforward.
I mean, the manufacturer of the printer should provide test patterns
with different options like -2,-1,0,+1,+2 and let the user choose the
one with the best alignment. This should result in an automatical
correction.

By the way, here are some more printer test patterns:
http://www.fho-emden.de/~hoffmann/raster16052003.pdf

Best regards --Gernot Hoffmann

 

[David Mathog]

thanks for your contribution. In the moment I can´t see how the
correction for the printer could be done straightforward.
I mean, the manufacturer of the printer should provide test patterns
with different options like -2,-1,0,+1,+2 and let the user choose the
one with the best alignment. This should result in an automatical
correction.

The printer that started this did have a test alignment.
Unfortunately at 1200 dpi the Y vs K alignment was
essentially unusable because it required aligning what
appeared to be a width 0 Y line against a width 0 K line.
Even on a dissecting scope with good lighting (something I
suspect most printer owners don't have ready access to ;-) )
at 1200 dpi I could not see the Y line well enough on the
white paper to do the alignment. It might have been more
evident on some other color paper but I didn't have any
colored paper to test that with.

So I wrote the test page, which in my hands anyway, is
easy enough to read without resorting to special optics.
The original idea was to print K and have
Y print over it. It turned out that most printers
don't do it that way. If they think the Y completely overlays
the K they don't print the K at all, and that's true even if
there's so much misalignment that the Y and K lines would
have been entirely separate.


You are correct that the printer must supply some way to adjust
the offsets and these are usually specified as you indicated somewhere
in the menu system.

Regards,

David Mathog
(e-mail address removed)