P600 + QTR on OHP Film...PK or MK?

[MurrayMinchin]

Hi there,

I'm going to be using an Epson P600 and QuadToneRIP with OEM inks to make enlarged digital negatives onto OHP film.

People seem be using either MK or PK inks...why would someone would choose one over the other?

For testing purposes I've been using Epson Hot Press Natural paper with MK ink, so would prefer using MK ink while making negatives on OHP film as well.

Made my first prints using QTR and Print Tool today (tad dark but in the ballpark) am getting UV LED's tomorrow, the OHP film should be here next week, the darkroom will have water in a week or so, then the chemicals and papers to be coated after that.

Getting close!

 

[Andrew O'Neill]

PK.

 

[MurrayMinchin]

PK.

Any particular reason(s) why?

 

[fgorga]

It probably does not matter.

Back in the early days of digital negatives, MK had significantly more density in the UV than PK. These days the difference is small, but MK is still a bit more dense than PK.

If you are making your own curves, pick one and stick with it.

If you are using a curve generated by someone else, they should tell you which ink to use.

 

[MurrayMinchin]

It probably does not matter.

Back in the early days of digital negatives, MK had significantly more density in the UV than PK. These days the difference is small, but MK is still a bit more dense than PK.

If you are making your own curves, pick one and stick with it.

If you are using a curve generated by someone else, they should tell you which ink to use.

Ahhh, thanks for that. Makes sense and gives me some avenues for further information searches.

 

[Andrew O'Neill]

I read somewhere years ago when I first got into using digital negatives that mk had a hard time adhering to some OH materials. Because of that, I've stuck with Pk. I'm currently running a 3800 and P400, all black inkset, and one yellow.

 

[MurrayMinchin]

I read somewhere years ago when I first got into using digital negatives that mk had a hard time adhering to some OH materials. Because of that, I've stuck with Pk. I'm currently running a 3800 and P400, all black inkset, and one yellow.

Good plan...after all the work figuring things out, why change, right?

 

[nmp]

If you print a test strip each with PK and MK, you will immediately see the difference. The MK: a) does not dry quickly - requires hours before dry to touch; b) runs, particularly if you increase the ink density via QTR; and c) greater propensity for "pizza wheel" formation. All from my experience with P400 and Pictorico Premimium (TPU100), probably true to a certain extent with other combinations. The only reason I messed with MK was to increase UV density, which it did some but it was not worth it.

Good luck!

:Niranjan.

 

[ced]

Admitting my ignorance I had to hunt the PK-MK meanings down & fished this from LL (Luminous Landscape):
"The main difference is the reflectivity of the inks.
Photo K is designed to have a gloss that will be similar to the gloss of photo paper to help mitigate gloss differential.
For matte paper, the Matte K ink has an actual matte finish to help improved D-Max (Photo K on matte paper looses D-Max)."

 

[Andrew O'Neill]

I've never noticed any drying issues with MK, P400 printer, and the OH material I was using. Mind you, I had QTR set to print very little of it, compared to PK. Once that MK was done, I stuck in refillable cartridges, and converted to all blacks (PK, LK, LLK, and yellow).

 

[Dan Pavel]

I have used both on Pictorico (SC-P600 printer) and didn't noticed any big difference. Both are very effective UV blocking inks. However, the curves applied to the DN were slightly different for PK an MK.
By the way, I couldn't make QuadToneRIP work with SC-P600. It apparently support the printer but somehow fails on the run. However, the "Advanced B&W " mode of the printer, using only black and gray inks, is very predictable - sort of QuadToneRIP preset, I'd say.

 

[MurrayMinchin]

I have used both on Pictorico (SC-P600 printer) and didn't noticed any big difference. Both are very effective UV blocking inks. However, the curves applied to the DN were slightly different for PK an MK.
By the way, I couldn't make QuadToneRIP work with SC-P600. It apparently support the printer but somehow fails on the run. However, the "Advanced B&W " mode of the printer, using only black and gray inks, is very predictable - sort of QuadToneRIP preset, I'd say.

Thanks for the heads-up regarding different curves if using one or the other.

Holding my hand through this endeavour is Ron Reeder and Christina Anderson's book, 'Digital Negatives with QualdToneRIP', in which they say, "This book will focus on profiles for the P800..." so I expect our P600 should be doable.

https://books.google.ca/books/about..._QuadToneRIP.html?id=pK73DwAAQBAJ&redir_esc=y

 

[lloyd]

just a fyi for those interested: Bill Schwab has a series of videos on youtube on making dig negs with QTR that are very informative. Pretty much spell out the workflow, easy to follow.