Things You'll Need
Inkjet or laserjet water-slide decal paper
Clear acrylic spray
Paper towel, rag or sponge
Using your computer and some specialty paper, you can add photos, graphics, cartoons or text to your favorite coffee mug by creating custom decals. You could also draw your own image and attach it to the mug. Although any color is appropriate for a decal, test your printer when planning your design to see which colors it prints best.
Open the decal design image in a photo-editing program on your computer, or scan the image into your computer if you have drawn the design by hand. The computer should automatically detect the scanner and give you options to begin your scan. Use the photo-editing software to reduce red-eye, adjust colors or soften the edges of the digital image if needed.
Measure the circumference and height of the coffee mug, and use the photo-editing software to adjust the length and width of the image so that they don't exceed these boundaries. Do not measure the mug handle unless you want your image to go underneath the handle when you put it on the mug.
Load the water-slide decal paper into your printer so that when the image is printed, it will print on the glossy side. To test this, position a regular piece of paper in the printer and print the image to see how it turns out. Then print the design on the decal paper.
Spray the printed image with the acrylic spray and let it dry.
Cut out the dried image and place it in water until the paper backing separates from the decal.
Apply the separated decal to the mug, and blot it with a paper towel, sponge or rag until it holds to the mug. Let the decal dry.
If you like, you can draw on your decal paper before or after it is applied to the mug using permanent marker or paint.