Recently, when setting up a project for printing/cutting with the Roland VersaCamm, the black wasn’t true black. On screen all looked good, but when printing and cutting, the colour values on the black in particular were noticably not black.
After much trial and error, I found the following workaround recommended at the Roland site forums: create your graphic in RGB mode even when sending to a CYMK printer.
Hardly an intuitive solution, but it worked.
Colour Swatches in Adobe ought be RGB as well.
Set RGB values in swatches. Black is 0,0,0.
I don’t know why. Recent product updates to the drivers behind the printer or Adobe may be at play.
Adobe Illustrator set mode to RGB
When exporting as EPS, do not include CYMK data.