Frosting can only go so far when you decorate your cake. If you want to transfer detailed images to your cake, use wafer paper. It gives the cake a professional appearance and customizes it to fit your taste. Painting an image onto wafer paper using food coloring gives you a transferable image that is completely safe to eat. Anyone can do it with a little painting skill and a steady hand.
Clean off a counter space large enough to accommodate the wafer paper. Allow the counter to dry and set the wafer paper down. Flip the wafer paper so the rough side faces upward.
Fill small drinking cups with 2 tablespoons of food coloring. Stir 1/2 teaspoon of powdered sugar into each cup to thicken the food coloring into a soft paste. Set the food coloring next to your work area.
Draw your design with the food coloring pen as you want it to look on the cake. Draw onto the rough side of the wafer paper (it will look right when you put it on the cake). The color will show through on the other side of the paper.
Allow the food coloring to dry and flip the wafer paper over. The sketch should show through the wafer paper. Cut off excess paper that is just empty space outside the sketch.
Coat the sketch with piping gel. Use a soft bristle paintbrush to apply it.
Dip a watercolor paintbrush into the cups of food coloring. Brush the food coloring onto the piping gel, using the sketch as a guideline for the paint.
Flip the paper so the color image faces down and set it on your cake. Set it down slowly so you don't wrinkle the paper.
Wipe the back of the paper with a moist sponge. Wet the entire paper so it will separate from the piping gel, leaving the image on the cake's frosting.