It’s important to note that wax-free inks are necessary if you are foil stamping over a printed surface. High levels of wax in conventional inks will melt from the heat of the die. Rubber-based inks can also make your sheet practically impossible to stamp. If foils are to be stamped over ink, be sure to alert your printer so the proper inks are used. In fact, because of the requirements for this type of work, or work that butts or registers foil to printed areas, it is usually best to establish communication between the printer and stamper at the design phase.