Quadrille paper is a type of paper, often called graph paper, that is ruled in a regular grid of both horizontal and vertical lines, which usually extend to all edges of the paper, with no margins. It is often used in mathematics, for plotting graphs and various functions. This type of paper is often used for drawing diagrams or drawings to scale, as the regular grid of squares allows for scale conversions by arbitrarily setting the scale of the squares to the desired ratio.
The terms graph paper and quadrille paper are often used interchangeably, although this is not technically correct. Graph paper has many variations, including types with hexes, equilateral triangles for 3D perspective drawing, log paper, and engineering paper. Many types of graph paper do not have a regular grid of identical squares, but quadrille paper always does. The squares on quadrille paper are usually printed in light blue ink but may be other colors, such as black or green. The grid is sometimes partitioned by a regular grid of slightly bolder lines which group the smaller squares into blocks.
For many years, this type of paper has been used primarily by mathematicians and students, especially for graphing equations and functions. The regular grid of squares provides the perfect medium for expressing the results of such mathematical operations, using the Cartesian system of x and y coordinates and axes. The intersections of the lines of the grid serve as increments of various measures.
Paper of this type is commonly available in standard letter size, regardless of the region of the world where it is manufactured. Quadrille paper is made and sold with several variations to its physical packaging as well as the size of the printed grid. It may be loose-leaf and have holes for insertion into a ring binder or be bound in a spiral notebook or tear-off pad. The printed grid may be almost any size, although the most common sizes are four squares to an inch in the United States and six millimeter squares in other parts of the world.
While graph paper is most commonly used for scholarly pursuits, it has many other uses as well. Artists use it to lay out drawings, or to create enlargements or reductions of photos or drawings. It has many uses in crafting and sewing. It is popular amongst players of role-playing games for drawing maps and can be useful for hand-drawn charts, floor plans, flow charts, or schematics.