What does the gutter refer to in graphic design?

In graphic design, the gutter refers specifically to the space between columns of text or elements on a page. This spacing is crucial as it contributes to the overall readability and organization of the layout. A well-defined gutter helps prevent the visual crowding of content and allows for ease in navigating through written material. It creates a balanced appearance and ensures that adjacent columns do not interfere with each other, providing clear separation that enhances the design's effectiveness.

Considering the other options, the width of the paper pertains to the size of the overall page dimension and does not specifically address the inner layout design. The color contrast used refers to the relationship between different colors in a design, focusing on aesthetic and visual impact rather than structural layout. The margin of error in printing relates to potential inaccuracies in the printing process, which is more about production rather than the layout design elements themselves.