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

Forum|Forum|2 years ago
July 6, 2023
4 replies
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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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Correct answer rob day

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:

T

Test Screen Name

Legend

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

Correct answer

Community Expert

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:

rob day

Community Expert

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.