What is the design from which a weaver works called?

The term that describes the design from which a weaver works is known as the "pattern layout." This represents a blueprint or guide that defines how the threads will be interlaced to create a desired fabric design. A pattern layout gives clarity to the weaver about the arrangement and sequence of both warp and weft threads, facilitating the creation of intricate and visually appealing textiles.

Warp threads are the longitudinal threads that run on the loom, while weft threads are the crosswise threads woven through the warp. Plain weave refers to a basic weaving technique where the weft passes over one warp thread and then under another alternately, creating a simple diagonal pattern. While these terms are integral to the weaving process, they do not specifically refer to the design or layout guiding the weaver's work. Instead, the pattern layout offers the necessary framework from which the weaving takes place, making it the correct answer in this context.