Combination printing is a photographic technique of using the negatives of two or more images in conjunction with one another to create a single image.
Similar to dual-negative landscape photography, combination printing was technically much more complex. The concept of combination printing stemmed from the desire to create more of a fine art within photography and often more idealized images.[1]
Combination printing was popular in the mid-19th century due to the limitations of the negative's light sensitivity and camera technology. For example, the long exposures required at the time to create an image would properly expose the main subject, such as a building, but would completely overexpose the sky. The sky would then lack detail, usually appearing as solid white. Hippolyte Bayard, a French photographer, was the first to suggest combining two separate negatives, one of the subject matter and one of a properly exposed negative of clouds, to create a balanced photograph.
The technique was also used to create new, original compositions and provided new ways for photographers to be more creative with their work.
Later on, the technique paved the way for yet another artistic process, photomontage.