Once raw cotton has been ginned, carded and handspun on a drop spindle, the thread is used to mock-up the warp on a warping frame. Sections of neighboring strands are then bound together using lengths of raffia. The length of each knot seals a section of thread and the pattern of knots forms the intended motif. Each binding is tight enough to resist the indigo dye into which the threads are placed. In Indonesian and Malay ikat means to knot.
Indigo blue is an aqueous solution of the young leaves of the leguminous indigofera tinctoria plant.
Mama Katharina has eleven indigo vats. Each set of threads passes through every vat in one dyeing cycle. Katharina works and reworks until the color is right, a process that can take three years. Her threads are then saved to allow the color to deepen. Her oldest threads are usually eight to ten years old and it is these she prefers for weaving.