Thanks again Samuel. I will investigate the GCR of the media types. Great
help!
On Fri, Feb 7, 2020 at 1:25 PM Samuel Chia <inksandpaper@xxxxxxxxx> wrote:
You're most welcome! Most likely the LED lights will emit little to no UV
and very little violet light to excite any OBAs in the paper but the upper
floor is indeed of concern. There isn't much one can do about it. I also
suspect that few people, if any, will take issue with your prints given
such highly variable lighting, so I wouldn't worry too much about it, after
letting the client know the shortcomings of their choice of paper and
exhibition situation.
You can't directly see the GCR curves but you can print out test targets
with lots of neutrals (R=G=B) and near neutrals and study them with a
loupe. If there are lots of coloured dots relative to grey and black dots,
the GCR is not so high. There are limited choices of media types to give
you the best gamut and dmax for this paper, so one may be out of luck in
finding a media setting with low GCR.
Regards,
Samuel
On Fri, 7 Feb 2020, 18:04 Panagiotis Markolefas, <
panagiotismarkolefas@xxxxxxxxx> wrote:
Thank you Samuel!
Very useful information.
The exhibition hall has two levels. Both levels are lit by unidentified
and questionable quality strong led lights but the up level has also a
glass roof and during the day there is plenty of daylight.
Thank you for the suggestion of Acrylite OP-3 P-9. I will discuss that
with the client.
How can I check the GCR of the Canon PRO-4000 media types?
Thanks again.
Panagiovtis
On Fri, Feb 7, 2020 at 11:29 AM Samuel Chia <inksandpaper@xxxxxxxxx>
wrote:
Hi Panagiotis,
Will the 'various lighting conditions' have a UV or strongly violet
emission? If you can use glazing over the prints which is like Acrylite
OP-3 P-99 which filters out virtually all UV and attenuates a little of the
violet end of the visible spectrum, the OBA content of the paper will not
be excited and you can use M2 measurements to build the profile. This is
your best bet since you can't change the paper choice of your client.
Unfortunately, this will not help you deal with metamerism issues, best
to have high GCR as Daniel has suggested. I happened to see many samples
from the Canon Pro-1000 recently. It seems like Canon has reduced the
strength of its GCR across their various media types by quite a lot
compared to the iPF8400 which I own. Perhaps Canon was after a smoother dot
grain pattern for their newer printers, since previously this was a
criticism from discerning printmakers who compared Canon with Epson and
Canon was praised for this improvement with the new generation of Pro
printers. I'm not sure if there are any media type settings on the Pro-4000
which still uses as high GCR as the iPFx4xx series printers. Good luck with
that!
Regards,
Samuel
On Fri, 7 Feb 2020 at 16:35, Panagiotis Markolefas <
panagiotismarkolefas@xxxxxxxxx> wrote:
Thanks Graeme!
Unfortunately I cannot avoid the particular paper.
It is a customer choice!
On Fri, Feb 7, 2020 at 3:40 AM Graeme Gill <graeme@xxxxxxxxxxxxx>
wrote:
Panagiotis Markolefas wrote:
Hi,
I want to make with i1pro2 a printer profile for a paper full ofOBAs. The
paper is Hahnemuhle Baryta FB 350. It has a strong magenta cast.Most of
the prints will be BW and are going to be seen under various lighting
conditions.
if you are going to display under a multitude of different lighting
conditions, then you should avoid high OBA papers. There is
nothing a profile can do that can perfectly compensate for varying
levels of U.V. in different illuminants. Compensation can work
well when you have one, known illuminant. Best compromise would
be to identify a "middle of the range" illuminant in regard to
its U.V. content, and profile for that.
Daniel Pfeiffer's advice about using a high K separation
is good, assuming that you are driving the printer in
a CMYK mode.
Cheers,
Graeme Gill.
