Bad Profile Curve

[PrinterMike]

Our Epson 60600 has been banding so I tried making a new profile (which didn't fix the problem). I made the profile in Flexi Production Manager 21. In the final tab of the Color Pofiler it shows the cmyk curves. The myk curves look like typical curves, the cyan channel looks similiar up to 50% input and then tops out at about 40% output. I've tried profiling different media and putting heavy and light ink limits and it looks pretty much the same. What might be causing this (the cyan channel output to be so low)? I've attached a screen shot of the curve.

Thanks!

 

[Pauly]

are your nozzles firing properly

 

[colorcal]

Our Epson 60600 has been banding so I tried making a new profile (which didn't fix the problem). I made the profile in Flexi Production Manager 21. In the final tab of the Color Pofiler it shows the cmyk curves. The myk curves look like typical curves, the cyan channel looks similiar up to 50% input and then tops out at about 40% output. I've tried profiling different media and putting heavy and light ink limits and it looks pretty much the same. What might be causing this (the cyan channel output to be so low)? I've attached a screen shot of the curve.

Thanks! View attachment 170380

I think Cyan ink limit is to high. Reduce it (in second step of calibration - Ink Limit) and try to make calibration again. I think you should to reduce cyan ink limit by the 20-30% of current value.

 

[FrankW]

Not shure if the preview for grey component replacement is accurate. If the linearisation curve in the linearisation tab shows the same effect, it could be that the pigments in the ink has settled, and the cyan ink doesn´t get an appropriate density.

 

[PrinterMike]

Pauly - all nozzles are firing

Colorcal - I tried a low ink limit of 50% and one at 85% - similar curve in both profiles.

FrankW - the cyan channel in the linearisation tab looks good. Below is a screen shot of all channels on deltaE and output. I did not try shaking both cyan cartridges - but the ink level is VERY low on both cartridges (not to caution triangle level yet). I did shake the cartridges while printing some large cyan solids after the profile was completed.

 

[colorcal]

Pauly - all nozzles are firing

Colorcal - I tried a low ink limit of 50% and one at 85% - similar curve in both profiles.

FrankW - the cyan channel in the linearisation tab looks good. Below is a screen shot of all channels on deltaE and output. I did not try shaking both cyan cartridges - but the ink level is VERY low on both cartridges (not to caution triangle level yet). I did shake the cartridges while printing some large cyan solids after the profile was completed.

View attachment 170385
View attachment 170386

Now linearisation curves look promissing but you need to fix a problem with primery colors intensities. Flexi has a problem - it does not show the intensity of primary colors, e.g. as optical density values. If you want to make proper color calibration you need to start from proper values of limits=color densities. For ecosolvent or waterbased printers it mean colors should to have ~ C-1,3D, M-1,2D, Y-1,0-1,1D, K-1,5-1,6D. If the values are slightly different, it doesn't matter. the proportions for individual colors are important. The linearization curve does not tell us anything about the color at the zero point and the color at the 100% point - it only determines the characteristics. Pls try to finish calibration. In next level "Total ink limits" change one value (last one) only - set it to 300% and try to generate ICC profile. For ICC you can set total ink limit on 400%. If you have done the previous steps correctly, the profile quality will be the highest for TIL-400.

 

[ColorCrest]

Our Epson 60600 has been banding

Can you describe the appearance of the banding trouble?

 

[PrinterMike]

Here is a picture of the banding.

 

[PrinterMike]

ColorCal - I'm don't understand your suggestion. Are you saying I need to check the values of the ink limit test with my densitometer? How would that translate into Flexi's ink limit wizard?

 

[ColorCrest]

Here is a picture of the banding.

The banding trouble you're having is mechanical and not at all having to do with an ICC profile. Calibrate the media advance.

 

[Terry01]

That print is media related, not profile settings.

 

[PrinterMike]

Thanks for the replies. I have calibrated the media advance - how much pressure should be between the rollers and the media? I can move the rollers somewhat easily.

 

[Ron at Forest Litho]

Are you sure its not one of the other colors. If the blue is a mix, maybe it has a little Mag or Yel in it and the banding is coming from one of the other colors? and not the Cyan. Probably not in this case, but I once had it happen to me, Didn't realize there was just 5% of another color involved and it was doing the banding

 

[PrinterMike]

This morning I did the 500mm media adjust after adjusting the pressure to medium and we still get a light banding (not as bad as in the photo above) on vinyl. We did notice a slight roller impression on the vinyl at this setting (and did at the low setting too - though not as much as medium). I loaded a roll of paper and printed the same image with banding. Checked the roller pressure and it was set to hi (couldn't turn the rollers while pressure was on) so adjusted it to medium and did a 500 media adjust and still had banding. I've asked the operator to clean the rollers (we have never done that) but they don't look very bad. How long do rollers last? These are the originals with the machine and are very hard. How do you know if the pressure is correct for the material your printing?

Ron - the operator is going to do a test. The image we notice it on is a large cyan solid. I asked her to measure the color break down and make some images with the same ratios but using heavy magenta, then yellow, then black. I still don't understand why the cyan profile curve is bad (my original question).

Thanks for all the input!

 

[Ron at Forest Litho]

If you are using it all the time. the rollers should be round. If the machine is out of service for 6+ months and the roller pressure was on, you can get an impression in the roller from having constant pressure in one spot. The only other thing that might do it is if a sheet with a thick edge border got run thru and the machine squished it thru but it left an impression. Even if the roller has a bad bearing at one end it would not make such and even banding impression. I await the discovery of the actual cause.

 

[PrinterMike]

I think the rollers are OK - below is a picture of them. They are hard - I thought they would be rubbery. From the looks of the material - it is meant to be a hard roller. What else could be causing the banding issues? I haven't seen a response yet on the proper way to set the pressure of the feed rollers. Should there be no slip, a lot of slip when you move the roller? What feed roller pressures do you use for intermediate vinyl and also poster paper? I've seen encoder brought up before - could that be it?

Thanks for the help!!

 

[Ron at Forest Litho]

I dont think roller slip could be it, If it was that then the images itself would be noticeably distorted - like in the type, you could see it in the text letters. This does bi-directional printing right?
Maybe the head is a slight diff distance from the media going right than going left. Or something diff when its going one way vs the other. Are the bands the exact size of the amount of print it puts down on a single pass? If so then that must be it. Maybe the print head is loose or uneven at one end so it is lifting up going it one direction but not the other?? Question: There is no way to make it only print from left to right is there? Make it go to the end and then go all the way back to the other side and print the next band so it prints everything in the same direction?

 

[ColorCrest]

PrinterMike,
You are unnecessarily confusing two separate issues which one has nothing to do with the other. For answers of the machine itself, simply refer to its 170 page user guide where it addresses banding and media loading, setup, etc. For curves in Flexi, do the same with their user guide. Again, color mix has nothing do with your banding trouble.

The banding you've pictured is purely mechanical and a matter of proper machine setup and operation.

I'm sure with more experience you will learn to recognize the differences between machine banding, ICC profile banding, and inherent file banding.

Good luck.

 

[PrinterMike]

Ron - Good thought on the roller slip. We can print both directions or Unidirectional. The band is wider in bi-directional. When printing unidirectional it prints a pass, returns the head, advances the paper and prints a pass (I think). I'll look at the head when I get back to the shop.

ColorCrest - Good idea - I don't run this printer very often. I went back and reviewed and did all the media adjust settings according to the manual and still get banding (on C,M,Y & K) when printing on paper. The manual recommends running all material on the highest pressure setting unless you see buckling - so I made that change. I did the manual feed adjustment on paper and still get banding. So I also did the feed adjust while printing going from -5% to +5% and couldn't get rid of it. I could get it greatly reduced but not completely going when printing on Sihl Paper. Vinyl looks pretty good. Any thoughts as to what else to check?