If you would like any part of your print to be cut to a certain shape you will need to have a die-cut made. This is a custom made cutter which cuts the print to the desired shape. It is not just custom shapes that require a die-cut, any shape of print that is not a rectangle or square will require one.
Upper Case can however produce most work with round corners without resorting to a die cut. This is a very cost effective way of giving your printed piece a customised look without the extra cost normally associated.