Digital BW, The Print

Hello Paul,

I just ran swab tests of the UT FSN inks compared to FSN inks.  I 
found that the UT-FSN inks have the slight magenta tint (to naked 
eye) while the FSN inks are slightly blue/cyan.  Is this part of the 
ink design to give more of a selenium look?

And now for the mild dismay:

I happened to have some old MIS GP (glossy pigment) inks designed as 
replacement "UltraChrome" inks for the 1280 class of dye printers.  
These inks have been sitting around physically undisturbed for ~6 
months.  All color inks show a dramatic sign of settling.  There is a 
translucent (but colored) phase sitting atop an opaque phase of the 
same color.  The photo black does not seem to show this.  I have 
never experienced this before, even with the older pigments that have 
sat much longer.  So, is the colorant in the FSN inks likely to 
settle over time?

UT, UT2, and UT FS users, have you noticed settling?

Regards.

Shilesh

Shilesh,

>I just ran swab tests of the UT FSN inks compared to FSN inks.  I 
>found that the UT-FSN inks have the slight magenta tint (to naked 
>eye) while the FSN inks are slightly blue/cyan.  Is this part of the 
>ink design to give more of a selenium look?

Yes.  The general feedback has been that the slight "selenium" look is
preferred.  (Or, alternatively, people really dislike green prints.)

>And now for the mild dismay:

>I happened to have some old MIS GP (glossy pigment) inks designed as 
>replacement "UltraChrome" inks for the 1280 class of dye printers.  
>These inks have been sitting around physically undisturbed for ~6 
>months.  All color inks show a dramatic sign of settling...

I see settling in most of the pigment bottles I've had for some time.  I
always agitate before mixing or loading.  When I used a CIS with Piezo inks,
I agitated the bottles occasionally.  As far as I know the actual pigments
always have a higher specific gravity than the base.  The Brownian motion
and viscosity of the base is what keeps the pigs suspended -- for a while.
How long is a matter of degree.  The problem is accentuated with the GP
pigs, I would guess, because the viscosity of the inks was lowered (relative
to the MIS 7600 inks I use for the UT inksets) to make them more compatible
with the 1280.

It is a concern of mine.  I'm in touch with MIS and will soon be in touch
directly with MIS's supplier.  The problem does not affect desktop printers
using carts from what I can tell.  I think between the sponge and the
movement of the head, the inks are more than adequately agitated.

The only place I've seen a significant problem is with three large format
(7500) printers running UT1 -- one being mine.  If they are left to sit
unused for a long period of time, the tone will shift.  Interestingly, the
motion of the printers on the Epson stands appears to be enough to keep the
pigments suspended in the large format carts.  However, I was just contacted
by a printer who had moved his 7500 to a solid table.  The tone change
problem showed up.

For some reason I was never aware of the problem with the UT-FSN in my 3000,
which was on a table that did not move.  The only place I've seen a problem
is with UT1 toners and the 7500. 

So, I would not worry about the issue at this point.  However, I'm
definitely looking into the issue.

Paul
www.PaulRoark.com