In this method of weaving, the threads~ warp, weft, or both, are dyed BEFORE weaving, resulting in a design with soft blurred edges. In the 18th century, they were commonly referred to as 'clouds'. A 1749 Boston paper advertised " Fine cotton and Worsted clouded Wasitcoats" for sale.
This unique design concept was developed in 1740, as was called "chine' a' la branche" . By resist dying the warp threads only, delicate shaded floral motifs were achieved. Some even called them ghost designs
One can imagine the forethought and complex design process that went into weaving these beautiful fabrics. Sometimes the threads were dyed several times to achieve the desired design~ each time a resist paste or wax was used to cover the part of the thread that was not to be dyed. If you click on and enlarge this picture, you can see the background fabric is a single solid color. These are the weft threads, or while weaving, the threads contained in the shuttle that was passed thru the vertical threads on the loom(warp).