The term sepia tone refers to a photograph printed in brownscale, rather than grayscale. The resulting image is considered a monotone in shades of brown. Many old photographs were printed with sepia ink extracted from cuttlefish, and photographs printed in this style tend to evoke an older era. Most digital photo editing programs offer a sepia tone option, along with a grayscale conversion and other photo filters to enhance the look and feel of an image.
To physically print a sepia toned photograph, a photographer develops the print normally and then bleaches the paper to remove the silver from it. Next the paper is rinsed, and then soaked in a sepia bath, before being washed again and dried. The result is a photograph with a myriad of lush brown tones, and experienced photographers can play with the levels of development to achieve a specific look.
When a photograph is printed in sepia, it tends to look softer than it would in grayscale. The warm brown and gold tones of a sepia photograph also feel more alive to some viewers. Photographers before the advent of color photography often used a sepia bath for their photographs, especially portraits, to capture softer lines and appearance. Modern photographers use sepia to make a photograph look and feel older, or as a stylistic choice. In the modern era, sepia tends to be used more for landscapes than portraits.
While sepia is associated with a yellow or red tinge, true sepia is actually brown. As the photograph fades with time, the deep brown of the sepia leaches out, leaving a fading image behind. Depending on where the photograph is kept and what it has been exposed to, it may start to yellow out, or develop strong red tones. When these pictures were fresh, they would have been tinted in rich shades of brown. Photographers who physically develop their photographs in a dark room usually end up with brownscale photographs when they tint with sepia, unless they are knowledgeable about photographic chemicals and are able to manipulate the tone. Digitally, it is much easier to fade a sepia photograph so that it appears more yellow than brown.
Modern photography also uses sepia in a duotone technique, frequently with the colors brown and black, or brown and red. A duotone will have richer shadings of color because of the two color printing technique involved, and many photographs which appear at first glance to be sepia are actually duotones. Many art photographs are printed as duotones, because the image will appear more lush and saturated.