Prints are too dark - yes that old chestnut

Hello

I am a bit confused as to what is going on and not even sure how to explain the problem really.
Trying to print on Hahnemuhle PhotoRag Baryta using the Piezo Pro inks
Struggling to get a good screen to print match (even just something in the ball park would be great).
Yes my monitor (NEC MultiSync) is calibrated.
Problem starts with my machine (9800) that consistently prints dark. To illustrate this I am attaching a screenshot which shows the measured values from step one (i.e supplied PhotoRagBaryta Warm curve, print the 256 step target, dry overnight, measure in ColorPort with i1Pro2, import into PPEv2). As you can see shadows and three quarter tones are dark.
Go to step two (install new/linearised Warm and Cool curves, then blend new curves in PPE at 18/78 to create ‘neutral’ curve. Print another 256 step target using new ‘neutral’ curve. Dry overnight. Import measurements into PPE - result is much better but still a bit dark, see screenshot #2 below)
Step three - create ICC profile from new/linearised data, and install ICC profile for soft proofing in Photoshop.
This is where it gets confusing

If I open a file in Photoshop turn on soft proofing it looks dark and strongly contrasted. So I try and compensate with a curve and then print with ICC profile (i.e Let Print Tool Manage) but that seems to introduce a colour cast (cool) into the print?

If I turn on soft proofing in PS and select ‘preserve rgb numbers’ - i.e. linear - then it looks great, shadows are open and gradations soft and overall open and not dark.
But if I print image linear (with linearised curve) print is dark and shadows blocked and over-contrasty

Also, if in softproofing, if I turn ‘Simulate Paper Color’ then the image goes black like a mask - see attached screenshot #3 - this can’t be right?

Any suggestions would be great, thanks


Please share a screenshot of your actual printing process. If linear (preserve RGB numbers in soft proof) it should be “No Color Management” from Print Tool.

best
Walker

I think I may have discovered the problem
I printed an ink purge (‘8-ink-purge’) file and compared it to an older ‘ink purge’ print I had on file.
See attachment below.
The older ‘correct’ print is on the left and underneath
Wildly different across the board
The K channel should be different due to older print was with MK ink and I currently have PK loaded (and I am using a cheap matt coated paper for the purge print)
But the other channels should all be the same, but are dramatically different.
The Cool Dark has gone strongly cyan. All 3x Warm channels have ‘warmed up’.

(note- the CGO and LWm channels are remapped due to missing nozzle in Yellow channel)

I am guessing this is due to ink settling? Pigments separating out and settling to bottom of carts?
But system is currently unusable it this condition?

20190828_094657_resized.jpg

Yep. Ink settling. Need to agitate your carts every 2 weeks.

best,
W

Its strange because we do shake the carts regularly.I thought we where doing it at least every 2 weeks, possible that a couple weeks got sniped over last couple months?
Settling seems worse in carts that are running low.
Lessons learnt are firstly to be strict about agitating carts and second to keep a reference ‘purge print’ on file to regularly print a new purge print and check that the colour on individual channels is stable.

still not understanding though why checking ‘simulate paper colour’ in soft proofing turns my image black?

Simulate black ink is a hold-over from the CRT days and does not work properly on LCD/LED monitors.

There could have been batch change + settling between these two prints. We did reformulate Pro in late 2017 for better steric isolation of the particles (less settling) and this increased the cool chroma a bit (no difference in pigment though). You should never let your carts go below the halfway empty point on this printer for lots of reasons fyi.

You most likely have PK selected on your printer instead of MK (re: the top line).

best,
Walker