Welcome. We do provide ways to produce inverted artwork, along with ‘Ramp Length’ cut settings designed for stamp making. We will need further information about the artwork you are using to better direct and assist you with suggested workflows. 
For Image work, there is ‘Negative Image’
For Vector fill work, create a design with filled shapes, give it an outline so the fill inverts, mirror it, and run it. If you have thin stems on lettering in the design, you can add a small ramp in the cut settings (Ramp length) to slope the sides a little, adding support.