Re: MonacoPROFILER and UV
Re: MonacoPROFILER and UV
- Subject: Re: MonacoPROFILER and UV
- From: Graeme Gill <email@hidden>
- Date: Tue, 12 Sep 2006 10:35:52 +1000
Robin Myers wrote:
No, FWAs come in several "flavors", but they all work in a similar
manner as noted above. Their spectral effects differ, but their goal is
the same, to counteract the natural yellow appearance of paper and make
it look bright and white.
Note that paper manufacturers also add "shading agents" to improve
whiteness, as well. This is basically a selective coloring, often
in the green wavelengths, and reduces the overall reflectivity of
the paper but improves it's color appearance. It's often
used in combination with FWA. If you take a look at common
low cost office paper, it often has shading agents as well
as high levels of FWA.
The Axiphos web site has some good technical papers on this sort of thing,
see <http://www.axiphos.com/BrightnessReview.pdf> for instance.
Software corrections have to assume a particular amount of UV light in
the viewing environment or the colors will not match. Not all the
colors, but the ones where the paper component is most visible, such as
whites and pale colors.
The software has to be told how much UV to assume in the viewing
environment to have a hope of calculating things accurately. One
of the current difficulties is that there are no easily accessible
instruments for measuring the UV output of illuminants. Common
graphic arts instruments stop about 400nm or so, and they need
to go down to about 360nm to be useful for measuring UV.
Graeme Gill.
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Colorsync-users mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden