Kilims are generally woven with the slitweave technique. The slit refers to the gap left between two blocks of color. It is created by returning the weft around the last warp in a color area, and the weft of the adjacent color is later returned around the adjacent warp.
Weavers pack the weft tightly to completely cover the warp and often favor diagonal patterns so as to avoid weakening the structure of the rug with vertical slits. It produces bold, sharp patterns that weavers enjoy creating with more freedom allowed than a plainweave. This is also why kilims are so closely associated with geometrical designs even though there are kilims with floral designs as well.