HELP! COLOR SHIFTING PROBLEM WITH LATEX PRINTER......

[Bly]

It's the heads. The colour is accurate only right after calibration then forget about it.
Reprinting a panel? The colour probably won't match, or the length.
They are great printers but for certain jobs not the ideal solution.

 

[Andy D]

You can drop a couple nozzles between printed panels and have a noticeable color shift.
It's a good idea to do a nozzle check before every panel & as others have said, flip every other panel.
Butting your panels up in the shop prior to installing is an absolute must!

 

[dypinc]

Did you separate tiles in the rip or did you separate them before you brought them into the rip software? Sometimes separating them before bringing them into the rip can cause it to rip the colors at slightly different values even though they were created with the same values. Especially if that panel was a different size from the others.

Here is a screen shot of the prints presets.

Avoiding the lc/lm inks helps as well unless you really need them for smoothness.

 

[AKwrapguy]

color correction probably little over a month, print heads all have between 1100-1600 ml of ink fired, expect for one Y/M has little over 4000.

So the average for most Hp latex print heads is between 3-4 liters. So at 4000 ml (4 liters) your at the upper end of the average life. Since the color change that you seem to be having issues with is yellow, I would guess that that might be the issue.

 

[MonkeyB0y]

Ok

This is quite straightforward and easy to resolve.

Make sure you have the latest firmware loaded.

1. In onyx turn your gutters on and make them 6mm each side (confidence strips)

2. Make sure all your printheads are under 6l and they are firing correctly, if not change the head.

3. Go to your media/substrate options

4. Selected optimised for tiling, select your media, make sure you are running 12 pass, optimised for tiling will change the interpass delay to 1000 and add some other features for printing.

5. Run the mandatory colour calibration as prompted.

6. Run your job. I have complete these processes and have seen DeltaE values of less than 1.1 panel to panel.

Remember to make sure you have stable temperature, if the room is cold, get it and the media to 20C, this will also assist for more colour accuracy.

 

[Ahmed Samy Nagada]

I love latex printers but this is their biggest weakness....They use heat to cure the ink which is very sensitive to environmental changes, temperature, moisture, print speed, and so on. And because the printer runs over a period of time the latent heat at the beginning of a run is cooler than after is has been printing for awhile. I used to use an HP L28500 and it was way worse then the latest series of HP latex printers. My old one didn't use optimizer or have an on board profiling system, HP added those features to alleviate the issues you are having. So the solution sounds complicated but in practice it's very easy.

1. Print your panels in installation order...i.e. print panel 1, then panel 2, then panel 3, and so on. This minimizes the color shift as the printer heats/cools throughout the run. Any color variation is hidden because the panels that need to match were printed next to each other.
2. Rotate every other panel by 180 degrees. That way the left side of say Panel 1 prints on the same side of the printer as the right side of Panel 2. This helps minimize color shifts because as the printer begins each pass either left or right it takes a split second to be jetting the inks properly...so the left/right edges might have a color shift before the jets are firing properly. Also in a latex sometimes the heating elements are a little hotter/cooler on the left/right of the machine, this is more common the older the heating element gets and wears out. But rotating every other panel allows the right side of one panel to be on the same side of the printer as the left side of the next panel...reducing any color shift.
3. Lastly add a small printing gutter to each side of the prints. It's an option in your RIP software. This prints pure inks (CMYKLcLm or whatever your inkset is) in small strips along the edges of the roll. Again because the latex gets so hot and is so sensitive to environmental conditions that if you are running a print that is using heavy amounts of say Cyan but not much Magenta, then over the course of the print run the Magenta head is exposed to a lot of heat while not firing a lot of ink. Then when it comes to a point in the print job where it needs to fire the Magenta the heads take a bit to recover and fire the jets fully. But if you have the printing gutters then the heads a kept "fresh" and constantly supplied with ink and not drying up with the heat.

It sounds tricky but it's simply a matter of printing in order, rotating every other print 180 degrees, and clicking a check box in the RIP for the gutters. This will minimize any color shifts, and honestly I do these on all of my paneled print jobs regardless of the printer technology it's just a good practice and yields the best results reliably.

In some rips like Wasatch you have the option "rotate alternate tiles"


Sent from my iPad using Tapatalk

 

[AGCharlotte]

on my 310 Latex, there's a setting on the profiles called "Long Run Consistency Mode". It's a check box on the first page. This helped me quite a bit because the initial 3-4 feet of longer prints were different from the rest. Not sure the 365 has the same setting but I imagine it does.

 

[dypinc]

You mean Media Preset. First screen of Media Preset has this setting and it affects all print modes for that Media Preset. There is when creating a new Media Preset a selection for Tiling which forces this option and may do some other things to enable more panel to panel consistency. You choose an existing Media Preset when you create this so that your existing Output Profile will probably work fine with this new Media Preset for Tiling.

Will people every quit calling Media Presets, profiles which can be very confusing to those who might think your are talking about Output Profiles or Color Management settings on the RIP.

 

[AGCharlotte]

sorry my bad... the presets in the Substrate library on the machine end.