Laser Colour printing - CorelDraw - mesh/gradiant fill problems

[Cowtoon]

We got a new printer. Nice HP4600 ... does a dandy job with bitmaps.

I did a gradient/mesh fill in CorelDraw and the colour (blue gradient to white) is splotchy!

It prints great on the deskjet, but is real ugly on the laser.

I tried with postscript and with pcl6 and pcl5e print drivers. It's a bad print. Has anyone else run into this.

I spoke with Hewlett Packard ... they are stumped. They suggested I speak with CorelDraw,so, I'm also going to post with themto see what they come back with. Thanks in advance.

[Silence04]

laser jets are always crappy with gradients... at least from my experience with our HP8500


http://www.jdcgraphics.net/banner.gif

[Keyare]

That sucks! Is it postscript? Does it have at least 256 shades for each colour (can't recall that basic PCL has any more than 16!)

Try converting the artwork to a bitmap (right in corel) in the short term to see if it comes out properly - if it does then it's a driver problem. If it doesn't then your printer probably isn't capable of true fades.

[Cowtoon]

Well, it would appear that it's not specific to CorelDraw. I did a test from simple ol' Powerpoint and it did the same thing. The banding is terrible. There has to be a remedy for this. I'm calling HP back again.

[Cowtoon]

Keyare, I'll try converting to bitmap to see if that works and let you know what happens. Certainly, exporting to jpg or creating a pdf didn't help at all.

I tried three drivers, PS, PCL6, PCL5E. I actually ended up with better (but not good) results from the PCL5E, if you can imagine.

I entered 600 for the fountain steps, in the printer dialogue box.

[Cowtoon]

Converting to bitmap didn't help, but it was worth trying.

[Cowtoon]

I called HP ... they are still looking into it. It would appear that the gradient problem exists from all software. I then spoke with the dealer that sold us the printer. They've run into this before. Apparently it could be a voltage problem, so they are coming out tomorrow with part that supposedly will fix it the problem. They explained ... when there isn't enough voltage for the faint colours (low percentages of colours) the printer gets confused and doesn't know what to do with it ... hence the ugly interpretation and printout. It's certainly confused me!

I'll post what the part actually is, if it helps.

[Keyare]

Voltage problem? Wierd. Especially since they usually design printers to be used anywhere in the world with all sorts of voltages...

[Cowtoon]

I said I'd let you know how it all panned out, so here's the scoop. After spending several hours with HP with lots of minor adjustements and no change ... and a few visits with the supplier ... again with no change, it was decided that they'd swap it out for a new one. We did a test on another printer (Xerox 8400) to see if it would print gradients and it did. That was an attempt to rule out that the problem wasn't in the system.

The printer was replaced yesterday (same model). Yippeeeeeeee .... I can print my gradients and shadows. It took a bit of tweeking to get the colours right. Gradients with the pcl5c driver are just wonderful - even better than the deskjet! (that's a surprise). The other printer was just a lemon, I guess. In trying to get rid of pink - invading my gray shadows (K value only) I attempted to apply a colour profile and discovered that the driver (pcl5c) couldn't handle CMYK. So, I converted the shadow to RGB and it's all ok. I'm hoping that won't cause other problems.

Now, I'm trying to resolve printing pdf's to PostScript ... it's all bad - no gradients at all - extremely choppy - yuk. I'll keep struggling with it. Something's gotta give!

HP and the supplier still consider replacing the DC (direct current) controller. It would appear that it's been a problem with a good number of the HP CLJ4600, otherwise, the prints are very nice with the pcl5c driver.
Thanks for all your input.