While heat embossing a digital stamp image might be difficult, it is not impossible! See
Digital Stamp Embossing and
Digital Stamps for more information. While it is just possible to add heat embossing in the traditional way to digital stamp images that are printed onto non porous papers, the inks dry too quickly on porous paper for this to be effective. Therefore an alternative way to add heat embossing to digital stamp images is to use an embossing ink pen (or any marker pen with a slow drying ink). This pen can be used to draw around the outline of the printed image. While this isn't perfect (you will notice that even using a fine pen the embossing goes outside of the printed line), it is certainly an effective way to get an embossed effect on digital stamp images.
Materials Required
See the following pages for a step by step guide to embossing digital stamp images with an embossing pen and
Heat Embossing for more information about the heat embossing technique in general.