QTR-Quadtone RIP

One possibility is that you built and evaluated your profile when the ink was not totally dry on the Pictorico film. The transmission density will decrease as the ink dries out. And this would result in white highlights one day and gray ones the next.

If you look at a freshly printed negative from the back, you will notice a white milkiness in the inked areas. This will disappear as the negative dries. If you are just air-drying the negative, I would recommend at least a 12 hour wait before printing. You can accelerate the process by forced air drying with a hair dryer set on medium. That is what I generally do in workshop situations, and even then I recommend waiting an additional 20-30 minutes after it looks dry before printing.

Try re-printing some of your test strips used during your calibration and profile building phase. If they now print with murky highlights, I would say this is the likely culprit.

If not, simply use some black boost in your ink description to get that white you are looking for in your prints. If your K limit is now 55, for instance, crank the black boost to 6 and see where that leaves you.

--- In QuadtoneRIP@yahoogroups.com, "alxbk" <alxbk@...> wrote:
>
> Hello,
> 
> Maybe someone had a similar experience and can point out what I might be doing wrong.
> 
> So basically I was trying to polish a gray curve for the silver paper profile I'm working on, when I noticed that the whites are slightly muddy on the final print. The same profile was working just fine the day before, but now all of the sudden I can't get pure highlights in my prints. As if black inks can't master enough density to block the light completely. Default ink limit in profile is 100%, and so is K density.
> My first though was, something wrong with the chemistry, or the silver paper. So I placed a piece of black plastic over a portion of the negative, and that developed to pure white. 
> 
> So either something is wrong with the printer, or the profile. 
> I keep exact records of every change I do to my profile, so I went back to the point where my stepwedge print showed pure highlights. Reprinted it with the same settings and got muddy whites again.
> If anyone has any clue as to what else might be affecting highlights like that, please share.
> 
> The printer is 3880.  
> 
> Thank you.
>