[argyllcms] Re: Black turning down problem - help!
- From: Elena [service address] <1007140@xxxxxxxx>
- To: argyllcms@xxxxxxxxxxxxx
- Date: Thu, 06 Jan 2011 14:21:16 +0100
Hello Roger
On 5-Jan-2011, Roger Breton wrote:
> Elena,
>
> I admire your persistence. But I believe you should start with a better
> quality paper because the color will behave more predictably than on the
> cheap paper. Then, when you are convinced that profiling works on the better
> quality paper, you can try on the cheaper paper. But if I was you, I would
> take the easier path first.
I know mine are just "academic" obsessions, don't worry :-)
But I'm made this way. I'm also a theoretical, a researcher, and so on...
if the used approach/algorithm fails just because the paper is bad, I
suspect there's something basically wrong, so I'm concerned that the very same
wrong principle will someway affect good papers also, even to lesser extents.
I would be very disappointed seeing that a resulting profile made on
quality glossy paper, for example, computed from 4000-5000 patches, shows
a black ramping down at the end, even slightly, when I STATED that it must
go from 0 to 100% (if the case), with only slight deviations from a linear
state (I accept that because it would make a sense) but I expect that the
ending points are there, and the C,M,Y channels are computed as a function of
the K curve I choose to reflect a neutral grey, not that at some point K is made
bending down unnecessarily.
In addition, the theoretical point of view: what, if I would really like to
have also a good profile for plain paper ? One could be wanting it, of course.
Think of newspaper paper, for example. Is there around a more ugly and bad paper
than that ? But nowadays, web news printers too are very concerned of color
quality.
I don't think they would accept such a behaviour from a profile for their press.
And they perhaps also use a very low total coverage, of 200 maybe. I forced
even 300 for plain paper, with some printing trick. I wonder what would happen
here if I decided to try such a low ink limit... maybe that would even be
a solution, paradoxally !? I just have to try...
> Just beware of paper filled with optical
> brighteners, if you can avoid them.
I think that the -f option + usage of spectral data should be there for that,
if even not making miracles.
I don't think my problem is related to those, however.
/&
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