Stone Design Forums

Hello All

I have a PDF exported to V1.5 from illustrator CS2.
The file contains transparency in images as well as using shadow effects around some text. The resulting shadows seem to loose their correct transparency when processed through PStill. e.g What was originally black shadow overprinting background now seems to partially knockout (probably inverse to the strength of the shadow tone) against the background. I have tried all combinations of Take over Overprint and use transparency from PDF but I get the same result each time.
Other apps that I have seem to honour this transparency OK i.e Odystar & PDF Enhancer but I really need to use PStill for other reasons.

Any Ideas?

Regards

What I have found with PStill is it supports Alpha and not opacity I will try to explain how to demonstrate the problem. I have raised the problem before and have not got an answer so I bet it's complicated.

I have a copy of Create so I will use this as an example but I guess you can replicate this in Illustrator.

Drag out a rectangle

Select the Info -> Effect panel

Use the Multi tool to add a drop shadow, this allows you to alter the Alpha of the drop shadow and works when using PStill

Now add a fill to the rectangle, if I now bring up the Apple colour picker for the fill colour I can set the colour and the opacity. Opacity will not work for me in PStill.

Further investigation reveals that I can not reduce the opacity of the colour of a drop shadow when moving the opacity slider.

My work around is to use Apples pdf tools, I guess these are too basic for your needs, which support opacity and give a more reliable document exchange.

I have pdf version set to automatic and PDF/X is unchecked.

Hi Blond

I suspect you are right.
Perhaps to clarify.. what I really need PStill to do which I can't find anywhere else is to convert indexed images back to standard CMYK images. I know this sounds odd but I have a reason. By default PStill does this, it also replaces smooth shade objects with gradients which can also be quite useful. However this transparency/overprint problem is to risky to use in a production.

Oh well.

Regards

Try checking the "Preprocess PS" switch in Preferences -> Layout Options.

This runs the PDF through apple's machinery which can deal with shadow stuff.

Does not work for me.

No joy

A bit more info...

What seems to have changed is the blending mode of the image.
Originally it was set to Multiply with an alpha of 75%.
Pitstop Pro now reports the blending mode as normal with an alpha of 100%

Currently, we support only pdf-1.3 and pdf-1.4 transparency (smasks and
opacity setting for colorspaces) effects.

See

http://en.wikipedia.org/wiki/Transparency_(graphic)

for an explanation - PStill does takeover alpha and 1.3 opacity but is
limited to some degree by the PS language which has no full description of 'transparent' objects.

Most people in professional print are loathe to use transparency effects -
because they tend to produce different output on different output systems, as you have found.

Try using input as EPS or PS (e.g. from Create) because the
transparency effects are usually already flattened.

Feel free to send us the PDF in question and we can look at it - in the future we'll extend PDF-1.5 and 1.6 transparency just like Acrobat does when output to PS/EPS - that is, by rendering/blending
such elements to raster images.

Most commercial printers have an up to date copy of Acrobat. In my experience it is best to use Apples pdf output rather than PStill when dealing with other people. In my mind PStill is out of date and has always given me transparency grief.

Hi Andrew

Thank you for the clarification.
We are a pro print outfit and understand why a lot of printers hate transparency. However it is fundamental to our PDF workflow due to file editing, late trapping and colour management. Many files are supplied by clients and we ask for 1.5 or above files with as little transp flattening as possible.

Thanks again

PS How do I send you a test file?

James

This may be the reason most printers prefer work submitted in Quark or Indesign not pdf. But I am a Create user so pdf is the common ground.

Send it to andrew at stone dot com

I have a 2-page newsletter in Create, saved it to PDF, ran it through PStill to reduce the size. No matter what setting I try, PStill always renders black boxes (frames?) around the photos that are rotated.

I'm trying the Save As Postcript tip, but PStill has been running the ps file for about an hour and is still going.

Is it possible to have PStill render rotated images without the black frames?

Thanks,

That's odd. Send me the PDF to look at..

Oh - you have a semi-transparent fuzzy shadow on those photos - that's a PS Level 3 feature and may not be explicitly supported by PStill - so it's rendering black in PStill.

You could save the pages as 300 DPI images from Create - or maybe if you saved as PS and dropped that onto PStill, it might work.

OK. I changed the black border and gray "shadow" for a plain gray border, and that worked fine.

Thanks,