🚀 go-pugleaf

We received a PDF file from a Customer that includes white type that overlays a rich black background. This white type has a overprint mode of 1. The fill of the white type is as follows:

Cyan 0%
Magenta 0%
Yellow 0%
Black 0.1%

The rich black fill is:

Cyan 42%
Magenta 42%
Yellow 40%
Black 100%

For what I know about OPM 1 is that this white type should overprint all colors except for Black.

When viewing this file in Acrobat with overprint preview on the white type overprint all colors including the black.

If I change the white type separation to have a 0.2% Black fill and view the file in Acrobat with overprint preview on it previews as expected. The white type overprints all color except for the black channel.

Does Acrobat have a tolerance on the amount of fill an object needs in order to preview correctly?