[riscos-printing] Re: Gutenprint and Canon Pixma ip4000
- From: Martin Wuerthner <lists@xxxxxxxxxxxxxxx>
- To: riscos-printing@xxxxxxxxxxxxx
- Date: Tue, 20 Mar 2007 11:24:51 +0100
In message <527e1fc54e.wlm@xxxxxxxxx>
Willem Arends <wlm4p@xxxxxxxxx> wrote:
> In message <927d0ec54e.Derek@xxxxxxxxxxxxxxxxx>
> Derek Barnett <derek@xxxxxxxxxxxxxxxxx> wrote:
> I made the same Draw-file, imported it into Impression and printed it.
> All colours are printed, albeit a bit darker than on screen.
>>
>> If I alter the settings to:
>> Black = 0% Red 0% Green 0% Blue
>> Yellow = 100% Red 100% Green 0% Blue
>> Magenta = 98.8% Red 0% Green 98.8% Blue
>> Cyan = 0% Red 98.8% Green 98.8% Blue
>> They all print in Draw, but only Black and Yellow text print in
>> Techwriter.
First of all, please bear in mind that Draw, the Draw format,
TechWriter and the RISC OS printing system are all RGB only. If you
set a CMYK colour in Draw, the colour is converted to RGB instantly
and stored as an RGB colour in the Drawfile as soon as you click OK in
the colour picker. So, you have no guarantee that colours set in CMYK
arrive at the printer as specified above. For the above colours, that
is quite likely though.
>> Have used the 100% settings so that I can calibrate my printers, what
>> I see on the screen and any Photo's are the same.
I do not think the above colours are suitable for calibrating because
of all the colours of the world you have picked precisely the four
that are just the pure inks of the printer, so they are the least
interesting (if not even completely pointless) for calibrating.
Besides, how many photos have you seen that have pure magenta or pure
cyan in them?
> Could the culprit be TW?
No, definitely not. The first test Derek reported was that the 100%
colours did not print in Draw, so this problem cannot be connected
with TW at all. The reason why the 98.8% colours went wrong in TW is
just caused by the different way TW treats colours, which effectively
means that it prints them at 100%, which, as Derek reported, do not
print for him. The difference with TW is simply caused by the fact
that TW does not allow the full colour resolution but only a subset of
about 4000 colours, so 98.8% Magenta is simply rounded to the nearest
colour available in TW, which is 100% Magenta. Just to avoid
confusion: This limited colour resolution in TW only applies to text
and frame colours set in TW (which was until recently limited to as
few as 16 colours), not to colours in graphics, e.g., Drawfiles.
Martin
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Martin Wuerthner MW Software lists@xxxxxxxxxxxxxxx
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