Photo cupcakes are cupcakes that are frosted and also have a photograph printed on top, most often using edible icing or food-grade ink. In most situations, the photograph is printed on special edible paper, not unlike rice paper, which is applied to the top of the frosting and allowed to slowly melt into the frosting to create the illusion of a photo. There also are photo cupcakes in which the image is not applied to the frosting but is instead placed on the cupcake in such a way that it is standing or somehow three-dimensional (3D), although it remains an edible component of the treat. Many bakeries offer to create photo cupcakes on their premises, although there can be certain limitations in quality and color, depending on the printing method and the application procedure.
The process of making photo cupcakes starts by scanning a photograph into a computer application. This image is then resized and printed on special paper that is usually edible. The heat sometimes generated by the printing process and other mechanical factors requires that the paper actually be made of two parts — the edible surface on which the image is printed, and a more substantial backing that allows the paper to feed properly through the printer without tearing or becoming dirty from the rollers.
The ink the printer uses also is edible and often is made from some of the same ingredients as standard food coloring. Even though the ink is food safe, it is not intended to be eaten in large quantities. Some of the more vibrant colors that can be used also can impart a small amount of flavor to the frosting, because of the nature of the ingredients and the process used to adjust the viscosity so they adhere to the paper.
Once the image for the photo cupcakes is printed onto the paper using the special inks, the paper is cut to size and peeled from its backing. The thin sheet of edible paper can then be placed on top of the icing, where it is allowed to sit for a time. The icing needs to be relatively fresh at this time so the ink and paper have a chance to interact with the icing's moisture and actually soak into it, becoming part of the cupcake.
There are some limitations with photo cupcakes. Unlike the standard cyan, magenta, yellow and black (CMYK) printing inks, the range of colors that can be achieved with edible inks is more limited, potentially resulting in off colors if the image is not color corrected beforehand. Additionally, when the image merges with the frosting on the photo cupcakes, it can bleed and create blurry lines, obscuring fine details or giving a watery appearance to the image.