Digital BW, The Print

>> I love the sepia tone recommended by Maurice Hamilton which 
>> uses the Channel Mixer thus: 
>>     
>
>   
>> Red Channel: R+30, G+70, B+8, C+8
>> Green Channel: R+25, G+75, B+8, C+4
>> Blue Channel: R+25, G+70, B+15, C-2
>>     
>
>   
>> Is there a way that this can be duplicated using the UT2 inkset?
>>     
>
> You could probably get very close.
>
> Here is what I did to estimate how close UT2 could come to this.
>
> I first opened a new RGB file in Photoshop and made a middle gray, with RGB
> = 127, 127, 127.  I then applied the Channel mixer settings above.  The
> eyedropper read the altered middle gray as Lab L=62, a=4, and b=9.
>
> Then I pulled two old UT2 test strips that had been printed with, first,
> pure carbon and, second, the sepia toner.  EEM was used for the test strips.
> At Lab L=62 (the same density or lightness as the gray patch in PS when the
> Channel mixer was applied) the carbon Lab (a, b) = (2.7, 7).  The sepia test
> strip at L=62 read (8, 15), using the ColorVision PFP spectro.
>
> I put these two points on a graph with axes a and b.  I drew a straight line
> between the 2 points.  That line passed directly through Lab (a, b) = (4,
> 9).  This is exactly what Photoshop indicates the Channel Mixer settings
> above produce.  The mix that should achieve this is 75% carbon and 25% UT2
> sepia toner.
>
> So, for UT2, a curves set made up of mostly carbon (green curve in
> Photoshop) and a lesser amount of sepia (blue curve) should do the trick.
>
> Hope this helps.
>
> Paul
> www.PaulRoark.com 
>   


Thanks for the reply, Paul.  I shall let all of this digest, and then 
give it a whack.

Rem