Magenta it is physiologically and psychologically perceived as the mixture of red and violet/blue light, with the absence of green. In the RGB color system, used to create all the colors on a television or computer display, magenta is a secondary color, made by combining equal amounts of red and blue light at a high intensity. In this system, magenta is the complementary color of green, and combining green and magenta light on a black screen will create white. In the CMYK color model, used in color printing, it is one of the three primary colors, along with cyan and yellow,
Combination printing often necessary to add artistic techniques to photographs. Discussing the benefits of composition in the art of photography and using combination printing, Robinson wrote, in "Pictorial Effect in Photography", that the method of combination served to "produce an agreeable presentation of forms and tones, to tell the story which is to be elucidated, and to embody the spirit of what it is intended the picture shall represent or suggest." His writings show his knowledge and his passion for creating new content in his photos with using this process. During the Victorian Era, another proponent of the technique of combination printing