vignetter

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A device used to print photographs and illustrations with borders that fade gradually into the background.
2. n. One who makes or specializes in the making of vignettes.

Century Dictionary and Cyclopedia

1. n. In photography, any device for causing the edges of a printed part of a negative to fade away evenly and gradually into the background A form of vignetter may be interposed between the camera and the subject, so that the portrait will be vignetted directly on the negative. See vignetting-glass and vignetting-paper.

GNU Webster's 1913

1. n. A device used by photographers in printing vignettes, consisting of a screen of paper or glass with a central aperture the edges of which become opaque by insensible gradations.
2. n. A maker of vignettes.