Exporting PDF with Drop Shadows: How to Prevent Index Color Appearance in PDX1a Files?

[Ilavarasan B]

We use the drop shadow option for frames in single colour (B/W) files, but when we exported the pdf using the PDX1a setting, the Index colour automatically appeared in the PDF. Can anyone suggest how to resolve this issue.

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[Peter Spier]

I'm not a Pitstop user, so can't help much, but waht does Acroobat's prefligth say about the color in the shadow?

Any chance there's a color conversion to a new profile going on during the export?

[Laubender]

Hi @Ilavarasan B ,

why does the preflight profile in Pitstop makes an issue, even an error, out of an indexed color?

Indexed colors in PDFs are just like "normal" colors; just encoded more space efficient. Nothing to worry, I think.

Regards,
Uwe Laubender
( Adobe Community Expert )

[Peter Spier]

But it also seems to indicate a 4-color shadow, unless I'm misinterpreting the meaning of shading object...

[rob day · Accepted solution]

Hi @Ilavarasan B , The PDF/X-1a Standard requires that all color be either CMYK or Spot—the Output Destination profile list is limited to CMYK profiles when the Standard is set to PDF/X-1a. You have set your drop shadow color to the default [Black], which is a CMYK color with CMY set to 0.

The PDF/X-4 Standard allows Gray profile Destinations. You could export to PDF/X-4, and if live transparency is an issue, flatten the PDF in AcrobatPro.

[Ilavarasan B]

Thanks rob

[Test Screen Name]

Indexed colour is not an alternative to RGB or CMYK. It is a way of arranging the colours. So it is NEVER a fault in itself, even if a preflight profile happens to say so. If you need CMYK then indexed CMYK is fine. If it's PDF/X1-a then it should be indexed CMYK.  

[rob day · Accepted solution]

Hi @Test Screen Name , Also, the index color is a result of PDF/X-1a’s flattening— a drop shadow gets converted into a DeviceCMYK index color image when it is flattened. Filled paths export as DeviceCMYK:

A PDF/X-4 exported to a Gray profile probably passes @Ilavarasan B ’s preflight—no index color and only 1 plate: