Hep! Gray turns pink on wax-based laser printer

[ovelky]

I created a PDF from an InDesign file several different ways for a client and he still gets the same result -- all of the gray tones on this full color document turn pink, yet all of the other colors print normally when he prints on his in-house printers. Both printers are HP Laserjet models (2300 and 4600 respectively) which use wax-based inks. Has anyone else encountered this phenom with wax-ink based laser printers and if so, what can be done to remedy the situation? By the way, the PDF documents print fine on my standard inkjet printer...it's just this client's wax-based printers that are having the problem.

[PrintDriver]

Mine's not wax based but what profiles did you embed in the image files?

[ovelky]

There are no embedded profiles that I am aware of. All images are CMYK. My InDesign Color Settings say "North American General Purpose 2". I created several PDF types with the same results, including PDF X1a-2001 (the most basic and most cross-platform friendly PDF setting). I am using InDesign on a Mac, by the way.

[budafist]

When you view the separations for the grey colour, what are the percentages? If they are percentages of CMYK, could you change the greys to only K value?

[ovelky]

I did not create the grays with InDesign's transparency gradients, but rather they are Photoshop CMYK's (variations of the clients logo used as a background creating a kind of "ghosting" or "watermark" effect.) Although I suppose I could make the Photoshop files grayscale vs. cmyk, but a similar thing is also happening to another page where the "watermarked" logo uses a tint of yellow. (Both tints are approximately 10%.) And again, the pink effect only happens to the tint areas. All of the other colors on the pages print normally. And again, I emphasize that the tints print normally on a standard inkjet printer. It is only on the client's HP wax-ink based printers that this phenom is happening. I hope this helps explain why I have been so perplexed by this situation.

[budafist]

If for example, your grey is made up of 10% magenta, 10% yellow, 10% cyan and 10% black, I've found that some printers will print this with a pink cast. That is because 10% of yellow is next nothing. Yellow is a very light colour. Cyan is also quite neutral. Therefore the pink comes out the strongest at 10%.

That's what I've found with our xerox machines anyway. To correct it, have a go at manually colour correcting in the opposite differection. I would do about 5 variations (swatches of the problem photograph) and then pick the best one.

[Kool]

This sounds like it's definitely a printer specific problem. I would contact HP or search the net for the proper color profile to use. If you can't find that you may have to just figure a work around. Print out a sheet with a whole bunch of grays until you find one that prints right and then sub that into your files that go to that printer.

[budafist]

Oh, to give an example of what I mean:
PMS 670 is a very light pink. When converted to process colours, it is only 16% magenta.

PMS 600 is a very light yellow. When converted to process colours, it is a whopping 30% yellow. That is because yellow needs a whole lot more ink.

So the equal percentage values of pink and yellow in a single area should (under my theory) be more pink than yellow.

[ovelky]

With all the issues this client is having with his wax-ink based printer, I am beginning to think they would be better off just buying a cheap $100 standard inkjet. They could waste more than that in my time and effort alone, not to mention their own, footzing around with the mess. But then again, they are banker bean-counter types who are so tight even their shoes squeak. The only saving grace is they did have enough good taste to recognize a good design job.