Printing Grey with HP Latex 360

Greys on a 360 should be pretty neutral without too much trouble.
Do a calibration on the printer and it should be good to go unless your profile is out of wack.

 

The 360s can make a custom profile by pressing a couple of buttons - maybe you should do that.

 

It may help consider the analogy comparing your printer against some sort of musical instrument; such as a piano.

I'm sure you understand musical instruments should be tuned using certain devices or by very astute expert technicians. Pianos are normally tuned to the frequency of 440 Hz which is the musical note of A above middle C as a standard for musical pitch. The remaining notes are tuned to scale.

Your printer is aimed to calibrate (tune) to a gray scale beginning with black, through the grays, to white. In your case of the HP, you should be able to use its onboard calibration device and method to bring the machine into tune. If that actually works, an ICC output profile from a third party (Avery) should be able to "tune" the remaining colors other than gray. Realize however, the third party profile will only be accurate if the machine they used as their basis was in the exact state of calibration as your machine's state of calibration. Know also that if you make your own profiles in-house, your profiles can correct and compensate to a surprising degree of calibration deviation.

With Caldera, you should be able to temporarily turn off any ICC output profiles to then make a print of a quality evaluation PDF in order to visually check the basic calibration of grays and color from the current state of your printer. If grays appear neutral, that fact should prompt you to then turn on the Avery profile and print the same PDF for comparison. In either case the exercise will tell you where you stand. Tune (calibrate) the machine or use a better profile. (You should not expect to "tune" or "fix" a profile.)

Other than that, a piano should actually be tunable and the performer should actually know how to play it.

 

Not meant to offend, but being blunt, this is not a failure of machine it is of operator.

You are running a piece of equipment, with limitless variables and expecting your ideal of perfection. This is a recipe for disaster! You need to control every step of your process if you expect to output your expectations, no matter what print tech you choose. Simply changing print technology may or may not solve your issues, but defining a process, instituting your management methods, and maintaining color calibrations will ensure proper output.

To go to your issue at hand, it sounds like you are trying to print a pure K grey. If that is the case have you tried defining Pure Hue K in Caldera so it knows to only use the K channel and not a build?

 

Im still not convinced there is a valid reason with todays printers to design in cmyk. You take pictures with digital cameras for your images in rgb. You design and view on a monitor that is rgb. RGB is the the widest possible color space where CMYK is clipped. Every rip will convert to its working cmyk color space to output...why clip your color before the rip does?
If you create a file in your application to 0, 0, 0, 80 for black, the rip will absolutely convert it to its cmyk version of that black unless you follow 2CT's instructions for pure grey. The l265 can absolutely give you a neutral grey from a build with minimum effort. It starts with a solid profile, I create my own using the onboard through Onyx. You can do the same in Caldera. Its an extra step but you are able to scan more patches ten just using the onboard. You need to color calibrate or re-linearize that profile very few rolls.
The heater settings on the printer can affect color. Most downloaded profiles are too high...imo
How does the print look before lamination? Some films can have a slightly yellow cast to them.
Running to a Mutoh won't solve your problems. It just gives you less options to correct...no onboard spectro...means you are forced to use a canned profile or a profile that does not match your media.
Go to HP's latex website and youtube....tons of videos and how to's for color. I am assuming you are not getting much help from your reseller or HP for this issue or have not reached out to them yet.

 

My 2 cents worth. Grays? As cmyk or Pantone? I've found that Pantone grays are much better. Probably something to do with the way the default RIP converts the Pantones.
p.s. NEVER EVER USE

C0
M0
Y0
K100

for black.

 

Wait, why not?

 

You'll end up with a "murky brown"

Best result is with
R0
G0
B0

or

C45
M45
Y45
K100

 

I see. I find my 100k black works just fine at 20p, but we all know to never run these at 20p!
I have a customer who has a 'charcoal' material from Johnson Plastics, that wants everything in the hospital to match this plastic. Luckily it's pretty close to duranodic bronze, which can be simulated on a 560 by running 90k at 20 passes.

 

You are buying ink and supplies from someone that is selling HP...leverage that for some training. Any reseller would swap some free training for consistent consumable orders....

 

Only thing that does that is, rendering intent.

Open up your color space menu and see what your rendering intents are for CMYK vs RGB.

 

Typically, rendering intents should have no effect here regarding grays.

 

It will have massive effect if he started in CMYK with one intent and switched to RGB with a different.

 

Then you and I must have a different understanding of the term "rendering intents." Rendering intents for me come from the ICC profile perspective of the 4 available options; Perceptual, Colorimetric, Saturation, and Absolute rendering intent.