A flatter is a coloring specialist within the comic book industry that prepares the inked or sketched comic book page for the colorist with digital art software such as Adobe Photoshop by selecting the objects on the page and filling them in with a solid color called a "flat" so that the "flats" can be used by the colorist by way of the "magic wand" tool as a way to select each object during the rendering process to the exclusion of the other objects on the page so that the object's base color may be changed or so that the rendering may be accomplished.

Because each colorist has preferences as to how the flats are to be done flatters usually work as freelancers commissioned directly by the colorist.

Pricing for flats vary but as of early 2010 one common going rate for a flatted page was $15 if the page were inked and of regular difficulty ($30 for a double page) with $20 dollars for a sketched page of regular difficulty ($40 for a double sketched page).

Notable flatters include Jeremiah Embs and Neil Fraser that obtained published credit for flats while working for the colorist Brian Buccellato on the comic book series Witchblade (issues #72, 73, 74) for Top Cow in 2003-2004 Anno Domini.