Digital BW, The Print

Paul wrote:
...
> Is it possible there was some actual magenta color still in the setup?
No, this printer has never had color inks in it.

Yesterday I refilled four of the carts (all but M and LM), and the fresh inks made an improvement. Lab A readings dropped to 1.6 on average, versus 2.3 before the refill, but still peak around 3 between 80 and 95.

Bizarre. The printer is used daily, and I shake the ink bottles before each refill to ensure the pigments are in suspension. I'm wondering if there really can be this much tonal variability between refills. The inks are near their expiry date so maybe that's an issue?

Mark 


--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Paul" <roark.paul@...> wrote:
>
> Mark wrote:
>  ... 
> > The one issue I'm still trying to resolve with the 1400 is a magenta cast (Lab A = 3 to 4 between 40%K and 95%K) on Canson Baryta Photographique. 
> 
> 
> I'm not sure where that would be coming from.  I used UT14 LC to make an "EZ" type of inkset for the 1100.  (See http://www.paulroark.com/BW-Info/1100.pdf .  I changed the name from EZ to avoid confusion with what MIS was offereing for the 1100.)
> 
> At any rate, I tested/profiled Canson Baryta with that setup.  The Lab A ranges from Lab A = 1 (the paper white) to Lab A = 1.95 (at 65%).  It ultimately drops as 100% black is approached.
> 
> Note that I always look at the values relative to the paper white.  This tends to minimize any read errors from the spetros.
> 
> > 
> > My setup is:
> > 
> > LC
> > C
> > M
> > LM
> > LLC = LC 50-50 with GLOP
> > Y=GLOP for second pass spray
> > 
> > The magenta seems to be coming from the M and LM inks, but when I reduce them the print gets cooler, so I lose neutrality on the Lab B axis.
> 
> 
> Assuming you have UT14 M & LM in your magenta channel, that would be standard MIS warm glossy carbon.  If just MIS glossy carbons are used, the Lab A can rise to over 4.  But there is where the Lab B is close to 14.  That is, it's a virtual sepia tone.  I doubt that has anything to do with a high Lab A in a near neutral print. 
> 
>  
> > Any thoughts? 
> 
> 
> Is it possible there was some actual magenta color still in the setup?
> 
>  
> > I love the Canson paper by the way, especially getting 97% of the tonal range between 0 and 100.
> 
> Baryta gives a very good paper white.  I like what I'm seeing in those papers also.  I profiled a Hahnemuhle Baryta with what I call the 1100 MIS K4-Quad (MIS K4 LLK, 2 LKs, and PK) the other day, and it made a near perfect sepia print.  I'll be getting a sample of Red River's new (don't know if it's out of beta yet) baryta paper next week.  I'm hoping its as good as the Hn. and Canson products.  If so, it'll save us some money.
> 
> Paul
> www.PaulRoark.com
>