Rug maps, or sometimes referred to as "cartoons" or a naksha are the blueprint of many newer carpets made today. In order to translate a design into actual weaving the designer must have a visual key for rug weavers to follow to produce the proper outlines and design elements of the rug. Often, it is sufficient to draw one quarter of the rug on a map, as each corner is symmetrical. Other rugs may have a half map, or rugs which are unidirectional have a full map.
Designers begin by deciding the knot density, then use a graphed paper with squares which represent each individual knot. The designer then pencils in the design elements in fluid curving lines, then goes back over the pencil to fill in continuous squares to express the lines in more simplified, pixilized form. Generally speaking, the tighter the knot count, the more curve linear the lines and advantageous the design may be. Therefore, a finer weaving often has a greater capacity to have more intricate details, and more flowing lines.
Seen below is just one isolated area of the field in a quarter map Naksha. This is often posted on the loom for weavers to read themselves without dictation from a talim, or spoken map. The full size of such a cartoon (only one area shown) is aproximately 2x3 feet.
Seen in more detail below, isolated areas have not been filled in because the design at this point has repeated enough times to follow other areas of the rug.
In the image below, you can see very clearly the original pencil lines of the designer (orange arrow), and how round flower design elements translate into squared off shapes in acknowledgment to the knots which will fill the space. Note the green arrows on either side toward the bottom of the image. These are small samples of yarn, color coded with the color of market to indicate which colors will be placed where.
It's a very intricate process, and a designer must carefully weight the type of design, and capacity of knot density to properly depict such design elements. Placement of colors in general have a great deal to do with continuation of outlines which are fluid, although on what would be considered a geometric grid.