What's going on with the gray on the L360?

[JERHEMI]

Please notice the attached pic. What's going on with the gray on the L360? Printing on 3M IJ35C with canned 3M IJ35C profile 8 pass.

 

[oksigns]

A warm gray. Is it a spot color or CMYK?

 

[greysquirrel]

manually upgrade firmware...360 just release another new one and all latest firmwares address color issues...

 

[Vinyldog]

How are the other forty nine shades printing?

 

[P Wagner]

What is it about this gray that you are referring to? Without knowing more (it it supposed to be a simulation of a Pantone gray, or a process build), there isn't much there to be able to help. Grays are a long-standing challenge for all digital large-format machines, and achromatic ranges (grays and neutrals) will be the first to look wonky when the printer goes into a non-linear condition.

If this issue centers on the color of the gray, the first thing to do is to re-calibrate the media (Front Panel > Settings > Color Calibration), and that should bring the machine back into a linear state.

 

[JERHEMI]

I'm sorry, forgot to mention...I'm referring to the bad banding in the gray. It might not be very visible in the pic, but WOW in person it's pretty noticeable.

 

[P Wagner]

I'm sorry, forgot to mention...I'm referring to the bad banding in the gray. It might not be very visible in the pic, but WOW in person it's pretty noticeable.

Hard to see the banding in your image.

With the HP Latex 360, printhead nozzle performance is almost always the root cause of horizontal banding. This is because media feed is consistently adjusted/ corrected by the OMAS sensor system, which for the most part eliminates the other key issue with banding that is related to media feed.

When ICC-based color management is in use (as is normally the case), grays are produced by mixing all four ink colors, CMYK. I would begin by troubleshooting which color(s) are causing the problem, by:

1. Produce an output sample using the attached file. Make sure that color management is not used (disabled in the RIP) when you output the file. This is intended to show which color(s) are missing nozzles, which would be evidenced by non-solid output in that color. Once the specific color(s) that are causing the issue are identified move to step 2.

2. Run one or more cleaning cycles on the colors that were identified in step 1. This is performed from the front panel ...> Image Quality Maintenance > Clean Printheads.

3. Run the internal nozzle test print pattern after the cleaning cycle has completed (takes about 1-2 minutes per cycle) by going back to the same screen as step 2, and choosing Nozzle Test Print. If needed, run this cycle twice.

4. If the offending head/color cannot be cleaned to get the nozzles back, it is likely time to replace that head/ color. This is a very simple 10 minute procedure with the HP Latex machines.

Increasing the pass count to a higher value would also minimize banding.

When printheads are operating correctly, HP Latex machines typically produce about the most consistent and uniform solid colors of any ink chemistry and printer platform that I have ever encountered including various brands of solvent, eco-solvent, traditional aqueous, and UV Curing machines.

Paul

 

[JERHEMI]

Hard to see the banding in your image.

With the HP Latex 360, printhead nozzle performance is almost always the root cause of horizontal banding. This is because media feed is consistently adjusted/ corrected by the OMAS sensor system, which for the most part eliminates the other key issue with banding that is related to media feed.

When ICC-based color management is in use (as is normally the case), grays are produced by mixing all four ink colors, CMYK. I would begin by troubleshooting which color(s) are causing the problem, by:

1. Produce an output sample using the attached file. Make sure that color management is not used (disabled in the RIP) when you output the file. This is intended to show which color(s) are missing nozzles, which would be evidenced by non-solid output in that color. Once the specific color(s) that are causing the issue are identified move to step 2.

2. Run one or more cleaning cycles on the colors that were identified in step 1. This is performed from the front panel ...> Image Quality Maintenance > Clean Printheads.

3. Run the internal nozzle test print pattern after the cleaning cycle has completed (takes about 1-2 minutes per cycle) by going back to the same screen as step 2, and choosing Nozzle Test Print. If needed, run this cycle twice.

4. If the offending head/color cannot be cleaned to get the nozzles back, it is likely time to replace that head/ color. This is a very simple 10 minute procedure with the HP Latex machines.

Increasing the pass count to a higher value would also minimize banding.

When printheads are operating correctly, HP Latex machines typically produce about the most consistent and uniform solid colors of any ink chemistry and printer platform that I have ever encountered including various brands of solvent, eco-solvent, traditional aqueous, and UV Curing machines.

Paul

Thank you! I will try these.

 

[eahicks]

Looks like a nice dark grey to me...guess we can't see the problem.

 

[Suz]

Oh good, it's not just me. I couldn't see it either. Read your post about 3 times thinking maybe I'm just slow, or my eyes are really bad.
Haha! Oh, I feel better now.