Colour casts

[GoonerGary]

I'm trying to get to the route of a problem which is causing a colour cast. All materials are top quality so it's not down to poor goods. It could be down to Adobe CS6, ink or a possible printer problem.

If I recreated the problem in Photoshop it looks as if I've gone into Adjustments/ Colour Balance and increased the Cyan by +50. I've ruled everything out and I'm confident the custom profile is spot on.

CS6 is known to have problems with colour casts, but I haven't found a solution... it could be a Mac issue only? I use Windows 8.

The printer is new and nozzle check is perfect.

That leaves the ink...so if the ink was faulty or out of date (mislabelled when sold?), what issues would you have printing? Could one of the inks be weak and cause a shift in colour?

[JMugs]

If your image is going green, you have a lack of magenta. This can still produce a perfect nozzle check. My problem was a blocked air inlet, hence I got a perfect nozzle check because it uses very little ink. When printing an image far more ink was required and a vacuum created which stopped the magenta flow.
The thread is some where.

Janners.

[GoonerGary]

My neutral greens are going blue/ green. Skin tones are going dark and reddish. So what colour of ink would that indicate a problem? The colour cast is not severe, I reckon most people wouldn't consider it a problem, but for professional jobs it would need to be right.

I woke up this morning thinking the carts might be to blame, they are large cityink refills for the Epson 4015. Can those chips expire? Could a faulty chip not deliver the correct amount of ink?

I found your thread and your problem was related to the CISS air vents, so can those vacuum problems happen within a non CISS refill cart?

[JMugs]

Thread is here http://www.dyesubforum.co.uk/vbforum/sh ... oing-green

On the back of your cartridges you will probably have 2 bungs, one for refill, one for venting. If the vent bung is still in and not replaced with a vent one or left open then that could be your problem. I assume your epson runs on a vaccum to draw ink and not positive pressure.

The other thing you can do is find a CMYK print chart that will print a page with just the pure colours for your cartridges being printed over an entire page as columns. This will show if you are having a poor feed from one of the cartridges.

Janners

[GoonerGary]

Yeah I've got one of those and a grey chart to help identify the shift in colour...I'll print that off later.

[GoonerGary]

I've printed a neutral grey chart and the greys are a warm purpley brown. In Photoshop you can recreate the look by increasing the Cyan by +50 (I've edited the first post now).

Here is the chart:
Greyscale printer test ramp (tiff - 300kB)
http://www.northlight-images.co.uk/down ... _page.html

I printed the CMYK chart above using Paul's profile and get solid black, bright yellow, dusty pink and pale neutral blue.

If I let the 'printer manage colour', the printout is much more saturated, the magenta is dark red and cyan is dark blue.

**Update, did tests and going into the file, Adjustments/ Colour Balance/ Cyan -25 gives a more neutral grey chart print out and the adjustment also corrected my test print print, so the greens are neutral and the skin tones have lost that redness...a little more natural now. I would need to do more adjustments to get it perfect.

So by compensating the -25 Cyan colour balance has helped a lot, but I shouldn't have to do that.

[pisquee]

You shouldn't have to do any of that, as the ICC is supposed to do all the compensation for you.
If the ICC has been done properly, and used properly, then any colour cast the printer gives will be compensated out by the profile, unless the printer has changed in some way since the profile was made.

[JMugs]

I don't use Ciss I use a wide format printer with refill carts. All reference to lines etc is where I stripped the printer. The air vent to the rear of my cartridge was blocked.

Janners

[pisquee]

... to expand on JMugs' post - adding a CISS to a small format printer is essentially mimicking the way a large format works...
On a large format you have cartridges of at least 100ml capacity (the large ink tanks on a CISS) which are fed through long lines/tubes to a damper above the print head (the refill carts on the end of a CISS mimick a damper)

[GoonerGary]

I think I can rule out a printer/ cart problem, I'm only getting a slight shift in colour. If it were a blockage of some sort I would be getting a massive shift like in your sample photos Janners.

So that leaves us with CS6, the profile or the ink. Can a profile be manually tweaked to adjust for the cyan without affecting the white balance?