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Graphics

Graphics comprise all non-textual design objects, including images, graphs, charts, shapes, and other graphical marks. Within documents graphics convey information, provide affective decoration, and establish visual structure. The placement of graphics is a primary way of establishing effective white space, contributing to visual order and balance.

An exceedingly important graphical matter, particularly for print documents, is resolution. Most images are raster images, which means that they are composed of multiple small dots (generally called pixels in digital design). Generally, computer monitors have 72 of these dots per inch, giving them a resolution of 72dpi. However, things printed at this resolution will look very blocky (or pixilated); printed material must be at a much higher resolution, generally 300dpi or greater. (This is why, for example, when you print out an image you find online it doesn't look as good as it might.) Documents designed for print must use high-resolution sources to ensure appropriate final version quality.

If you think of raster images as collections of dots, you can envision the direct relationship between its resolution and its physical dimensions (or size). As a raster image's physical dimensions increase those dots must separate and grow larger, which is why enlarging images leads to degradation of quality. Similarly, shrinking a raster image's physical dimensions compacts its constituent dots together, which allows the resolution to be increased.

Other graphics, such as charts and cartoon clip art, are commonly vector images rather than raster ones. Vector graphics are composed of mathematical equations and thus their resolution is theoretically infinite.