Why do some PDFs print cyan in transparent areas?

[FlorenceC]

So this'll be the second time I've run in to this issue - a client sends us a PDF and areas which appear white in RasterLink's preview (as well as Adobe Acrobat, AI), but when printed these transparent areas end up printing as cyan. Is there a setting I can change to either a) turn this off or b) at least see it in Rasterlink in order to prevent printing a crapload of unwanted material?

I'm running a Mimaki CJV30-160, with RasterLinkPro5SG.

I do try to print tiny proofs of everything, but I don't always have the time to do this and/or things come up in the office which pull me away from noticing until too late.

Thoughts?

 

[FlorenceC]

So this'll be the second time I've run in to this issue - a client sends us a PDF and areas which appear white in RasterLink's preview (as well as Adobe Acrobat, AI), but when printed these transparent areas end up printing as cyan. Is there a setting I can change to either a) turn this off or b) at least see it in Rasterlink in order to prevent printing a crapload of unwanted material?

I'm running a Mimaki CJV30-160, with RasterLinkPro5SG.

I do try to print tiny proofs of everything, but I don't always have the time to do this and/or things come up in the office which pull me away from noticing until too late.

Thoughts?

(As an aside, saving as a PDF/X does fix this, but you only know to do this after the fact and the whole issue just sucks if you aren't around 100% of the time to catch it.)

 

[Solventinkjet]

It's probably the rendering intent settings in Rasterlink. Rasterlink defaults to two different rendering intents for vector and bitmap. This is fine if your file is all solid objects as the RIP just renders whatever is on top. But if you have a raster transparency layered on top of a vector background, for example, it now has to render both objects. The problem is if it's being told to render each object with different algorithms, the mixed result usually doesn't match what the file looks like. If both rendering intents are the same, it fixes the issue.

I can't remember how to get there in Version 5 but it's a tab called, "Color Matching" where you can change the rendering intents. Mimaki calls vector images, "illustration," and bitmaps, "Image." Make sure they both have the same setting and see if that does the trick.

 

[FlorenceC]

So here's what it looks like to me - I've actually never changed anything in here. The two (illustration vs image) don't appear to be in disagreement, however.

 

[Solventinkjet]

So here's what it looks like to me - I've actually never changed anything in here. The two (illustration vs image) don't appear to be in disagreement, however.

That looks like it should be working fine then. It must be something different. I'd be willing to bet it's a color input or output profile though.

 

[Ronny Axelsson]

Transparencies sounds like a plausible explanation, they can create some unwanted effects.

Or is it possible that objects are set to Overprint perhaps?
I remember some years ago, a client sent a PDF where white objects were set to Overprint and they disappeared completely (of course) when printed.

 

[FlorenceC]

Just as a follow up here - I'm finding more and more Canva PDF exports are doing this and it seems to have to do with boxes which the client believes to be solid colour, but which have indeed (As Ronny suggests) set to overprint. Examining the boxes in question via Illustrator, the boxes have a '?' fill and no stroke.

Ultimately, now knowing the cause, the result is still the same. Barring editing either via Acrobat Pro or Illustrator, there doesn't seem to be an option for me to preview overprint issues via Rasterlink? Toggling overprint visibility in Acrobat also doesn't seem to highlight the issue.

 

[Ronny Axelsson]

Glad to hear you found what's causing it.
I suppose you don' t have CorelDRAW since you don't mention it?
If you do, you can select all objects, right click and disable overprints for fills and/or outlines.

 

[V. V.]

RasterLinkPro5SG

Better just change the RIP

 

[ColorCrest]

Ultimately, now knowing the cause, the result is still the same. Barring editing either via Acrobat Pro or Illustrator, there doesn't seem to be an option for me to preview overprint issues via Rasterlink? Toggling overprint visibility in Acrobat also doesn't seem to highlight the issue.

Try opening the original PDF in Photoshop. If Photoshops RIPS it correctly, the trouble is Rasterlink misinterpreting Adobe PDF technology. (Rasterlink is not a certified Adobe RIP? I dunno.)

 

[FlorenceC]

Glad to hear you found what's causing it.
I suppose you don' t have CorelDRAW since you don't mention it?
If you do, you can select all objects, right click and disable overprints for fills and/or outlines.

We don't - I can't say that I've personally used CorelDraw since the early '00s, to be honest. Our office is very firmly entrenched in the Adobe ecosystem.

Better just change the RIP

I wish I could! Unfortunately, I'm not the one with the wallet here. Which would you prefer instead?

Try opening the original PDF in Photoshop. If Photoshops RIPS it correctly, the trouble is Rasterlink misinterpreting Adobe PDF technology. (Rasterlink is not a certified Adobe RIP? I dunno.)

Yeah, I've had to rasterize in order to stabilize, either via PS or a straight PDF > TIF conversion via Acrobat.