Digital BW, The Print

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Aj" 
<ajkaya420@y...> wrote:
> Hi, just joined the group. Im looking for some suggestion on 
> minimilizing metamerism. I printing black and white images on a 
epson 
> 1280 using premium glossy photo paper and matte heavyweight paper. 
Im 
> currently printing straight RGB, I have toned prints in the past 
to 
> deal with the color shift, but I would like to print a particular 
> project without toning. Can someone offer some insight. Would 
> enhanced matte paper, printing at a higher dpi, and/or making a 
clor 
> adjustment help any?

I couldn't tell from your posting whether it was clear to you, so 
just for clarity and help for any newbies who might be reading this 
let's define metamerism:   Metamerism is the phenomenon of images 
having a DIFFERENT color cast under DIFFERENT lighting.   It's most 
noticable with black and white because we expect black and white to 
be neutral and notice when it isn't.   In the case of this group's 
most popular printer, the Epson 2200, prints commonly have a magenta 
color cast under "daylight" fluorescents but a green cast under 
actual daylight.   

You cannot fix metamerism with your choice of paper or dot-density 
because it's a characteristic of the inks.   It is caused by inks 
having a "peaky" spectral response, i.e., instead of the response 
curve being a smooth curve with its peak being at a particular 
wavelength, depending on the color of the ink, it has multipe sharp 
peaks and valleys. 

In the case of the Epson 2200 the worst offender is the yellow ink 
so you can buy RIPs for big buck$ that produce BW by minimizing the 
yellow.  I don't know which ink(s) is the villain with the 1270.   
You can also buy dedicated BW quadtone/hextone inks and turn your 
1270 into a dedicated BW printer.   

Or you can print using the black ink only (so called "black only" 
printing).    Note that many people find the dots and coarseness in 
the midtones objectionable with this method.     I recently did some 
experiments showing people black only prints and also showing them 
VERY small text - approx .85mm high - which is just at the limit of 
what people can read with the unaided eye.   Sure enough, the people 
who objected to the dotting were the same ones who could read the 
text and those who could not read the text thought the prints looked 
fine.   This confirmed my theory that whether people find BO 
printing acceptable may come down to visual acuity or whether they 
need new glasses.    

See my website for a discussion of some of these issues:
http://studio-nelson.com/inkjet/bw22001.htm

(At the time I wrote it there were no 3rd-party BW inks for the 2200 
so they were not discussed.   Also N.B. that the Epson RIP appears 
to have been discontinued by the company)