The common starting materials are tungsten trioxide (WO3) and tungsten blue oxide(WO3-X), the latter being the most widely used material.
Ang karaniwang mga materyales panimulang mga Tungsten trioxide (WO3) at Tungsten asul oksaid (WO3-X), sa huli pagiging ang pinaka-tinatanggap na ginamit na materyal.