Digital BW, The Print

Having read through the following I find it interesting that we have, on
this forum, feared the use of yellow ink.  I thought that this was due to
its perceived longevity weakness.  Yet the below suggests that this is not
the case (of course, only in the case of the particular pigment ink tested).
The article also highlights the issue of using diluted ink formulations
rather than normal density formulations of lighter coloured pigments.

http://www.imagepermanenceinstitute.org/sub_pages/inkjet_stability_72dpi.pdf

A test of the fade rates of individual inks rather than composites would
highlight whether a manufacturer's inks are relatively strong across the
board or whether they are, say, strong in some colours and weaker in others.
I'd really like to see MIS K4 vs Epson K3 (and even the new Nanochromes) on
this basis.  As opposed to Barbara Voigt, we know how to easily print the
pure colour strips with QTR or IJC/OPM.  How much room do you have in your
test facility Paul?  Maybe we should all pitch in and help you build a
bigger one....  ;-)


> From: <hogarth@...>
> Reply-To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
> Date: Fri, 30 Dec 2005 13:51:01 -0500
> To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
> Subject: Re: [Digital BW] On Paul's MIS vs. K3 fade tests . . .
> 
> Paul Roark wrote:
> 
>>> I too would like to see how linear the rate of fade is.
>>>    
>>> 
>> 
>> I have a 600 hour read of the K3 ABW and UT7 test strips.  Consistent with
>> everything we've seen, the rate of fade at the beginning is typically not
>> the same as later.  I usually assume that the fade rate is higher at first,
>> but I've occasionally seen apparent increases in density initially, even
>> when the printing was done over a week prior to the fade test start.
>> 
> It's conceivable that the increases in density seen early on are the
> result of driving off the last of the glycols and glycerins. Even
> moderate levels of light can increase the temperature of the print.
> Increasing the print temperature helps these ink base components dissipate.
> 
> I say this because I've noticed a fairly marked improvement in Dmax on
> my prints when I dry them with a hairdryer. Even days later - you can
> smell the glycols coming off the print and see the Dmax increase. For
> reference I'm using PiezoTones mostly on HPR. I've seen the same effect
> when drying UltraChromes however - not as marked, but a subtle increase
> in Dmax and a slight increase in gamut.
> --
> Bruce Watson