Quad-ruled paper

Quad-ruled paper is paper that comes pre-printed with a grid of perpendicular lines.

Quad ruled paper is particularly useful for hand drawing of graphs, charts, diagrams, and drawing geometrical shapes accurately. It is often used by students in helping them draw plans for various complex and simple things, from sample buildings (civil engineering) to an imaginary low-friction car (physics). Quad-ruled paper is also popular for simply taking notes, as the grid helps writing neatly.

Different grid spacings are available. The most popular form has lines 5 mm apart. Quadruled paper with lines 1 mm apart, and usually a slightly thicker line every 10 mm, is also known as millimeter paper or graph paper, and used for drawing high-precision charts. In North America, there are also non-metric variants with 4 or 6 squares to an inch sold.

The type of paper used mostly depends on the local traditions and paper availability. The choice may also be affected by economic reasons, too: usually one line of writing is written between two grid lines, so reducing square size may reduce paper consumption. The papers may be sold as notebooks or loose-leafed. Loose sheets usually have punched holes for archiving.

In many countries, quad-ruled paper is the most typical paper type used by schoolchildren and students of all ages. It is often associated with studying in popular culture. Graph paper, a special type of quad-ruled paper with a very small square size (usually 1 mm), is associated with engineering profession, on the other hand.

Very rarely, artists have used quad-ruled paper for drawings, though its use in making preparatory plans or drawings for what will be the finished work of art vastly outstrips this, and its use for doodling by bored students outstrips the two of these uses put together.