For the Polaroid emulsion lift process, a Polaroid print is boiled in hot water until the photographic emulsion - the light sensitive coating that holds the color and form of the image - begins to bubble. Then the Polaroid print is transferred to cold water where it soaks until the surface emulsion may be slowly rubbed off of the paper backing, leaving just a fragile membrane of color. Finally, this translucent, colored emulsion is placed on watercolor paper and carefully flattened into place. Five to twelve Polaroid prints are used to create a larger composite image. The final result is different each time due to the way the emulsion attaches to the paper; thus each piece is unique.