According to Strategic Publications Designing for Target Publics, alignment refers to the layout of items along invisible but easily identified lines. There are four types of alignment: horizontal, vertical, diagonal, and curved. Horizontal alignment places emphasized items of a layout straight from left to right, creating a visual line horizontally. Vertical alignment places emphasized items of a layout straight from top to bottom, creating a visual line vertically. Diagonal alignment places emphasized items of a layout from high on one side to low on the other side, creating a visual diagonal line. Curved alignment places emphasized items of a layout in a curved pattern often outlining curved art, which creates a visual curved line on the page.
Alignment is important to a good design because it makes items appear more unified. Readers’ eyes follow the invisible lines with their eyes, making a straight path through the page. Keeping photographs and other items aligned enables readers to view them together and increase unity. Alignment makes a design appear organized and is easier to understand. According to Robin Williams, who coined the term C.R.A.P. (contrast, repetition, alignment, proximity), alignment makes the page look sharp. Without alignment, the page looks messy. Alignment keeps the readers’ eyes follow through the page in a sequence, that way the information displayed is comprehensible.