First you need to get the material itself, which is supplied from quarries in the form of blocks. It is necessary to choose the raw materials of the desired shade, variety, size, which will make a monolithic windowsill. A slab is created from such a block — a workpiece. To do this, it is split into plates. And already from this slab, the window sill itself is made in the future, which in all parameters must correspond to the order.