How precisely the design is transposed to the workshop sketch, on the basis of which the master-weaver weaves the work, depends on the work of the artist making the workshop  sketch. Before the weaving begins it is decided how dense the warp of the tapestry should be. Density is measured by the number of the threads per centimetres. In the Middle Ages the density of the warp was 4 or 5 weft threads per centimeter, while in the 16th century, a time when finely shaded works were executed, as many as 12 weft threads were used per centimetre. The density determines the amount of thread necessary for the warp. The colored weft yarns are completely covered by the warp as they are densely stacked in one another by the fork. The pattern  is created by the  colored weft threads, which following the plan drawn by the artist, are loaded  and stacked line by line.