The polyurethane rubber will allow you to use the mold very easily, does not require the use of release liquids, as it is self-releasing thanks to its flexibility, and will allow you to create numerous square meters, without the mold undergoing signs of wear. . On the other hand, if the place will be external, it will have to be mixed with water, cement powder and sand, generally with a ratio of 1: 3, but the proportions are also variable depending on the humidity of the sand used. It is advisable to color the plaster or cement tile after its realization, using iron oxide powders, of at least 2 different shades, to be applied on the tile after the realization (on our e-commerce you will find a wide assortment). • Make the individual stones adhere by applying pressure and at the same time m.