"Jonathan L. Parker" writes:

Had worked passably (slow and used too much ink but print quality was
OK) for most of the past seven years on a MacBook Pro originally
running OS X 10.4.11. Still worked when I upgraded to Snow Leopard
and Gutenprint 5.2.9. All of a sudden, however, it won't print in
color. When I try I get only a black-and-white image that's way too
dark and pictures that almost look like photo negatives.

Among the things I've tried are completely uninstalling and
reinstalling Gutenprint, resetting the printing system, trying both
ColorSync and Vendor Matching under Color Matching, changing Color
Model between RGB, CMYK, KCMY, Republican, Democrat, Indepenedent or
whatever else is in there. In short, I've played around with anything
that looks like it might help.

I've got several other printers that still work fine with OS X and the
BJC-50 works just as great as ever with Windows (95, Vista and 7) so
my guess is we're looking at a software problem such as a setting that
somehow got changed. Any ideas where to start?

1. In your CUPS interface make sure you are using RGB for color, not
CMYK (gutenprint expects RGB and converts any other input to RGB
anyway---but CMYK is a much smaller color space so you would be losing
quality before you even began to print).

2. Make sure the resolution mode you are using is compatible with the
media, and with color. I.e., if you are using a monochrome mode it will
not matter what color options you are asking for, the specified mode
takes precedence.

3. Set CUPS debug option on in the admin panel.

4. Do a print and look at the debug log, also available from the admin
panel. Maybe you can see what the gutenprint output was specified as.

BTW, since I am current maintainer of the canon backend in gutenprint, I
would welcome any testing you could to. Pre-release of 5.2.10 is out too
(but for MacOSX it is missing the intelligent back-end required for the
various dye-sub photo-printers).

Regards,
Gernot Hassnepflug
--
NNTP on Emacs 24.3 from Windows 7