I want to verify that what I am doing is a feature so we can document it as part of our process for creating CMYK PDF's with the color "black" specified in the CSS.

When I specify the color "black" in the CSS in the following ways:

color: black;
color: prince-overprint(black);

And set the "prince-pdf-output-intent" on the @prince-pdf to a CMYK ICC profile the output for the text and objects set to black is converted to gray (0.0).

Of course this value obviously is not ideal when sending the PDF to a press because they end up needing to convert it to cmyk(0,0,0,1) during their RIP process.

However if I add the following to the @prince-pdf property:

prince-pdf-color-conversion: output-intent;

The text and objects set to black are converted to cmyk(0,0,0,1). This is what we want to be able to do but I want to verify that this is a documented feature of "prince-pdf-color-conversion" and not something we need to worry about going away in future releases. It appeared that other background-colors we specified in RGB are converted to CMYK without the " prince-pdf-color-conversion."

If you could verify my assumptions and explain to me what this property is supposed to be doing that would be helpful.

The CSS color "black" is sRGB black, i.e. rgb(0,0,0).

The initial value of the prince-pdf-color-options property causes CSS colors of the form rgb(n,n,n) to be encoded as a color in the DeviceGray color space. It doesn't depend on the PDF output intent.

When performing color conversion to a CMYK target profile, we do deliberately convert gray values to a K-only CMYK value, so you can depend on it.

Thanks. That is great news, I really didn't expect less from you guys, thanks again for a great product.