The shell can be built through dropping the assembly into themelted ceramic slurry as well as coated with good ceramic refractory. Equal to eight added coatings are given to provide additional strength to the applied shell.The most important stage of this shelling procedure is its primary coating, in which textured sand of extremely good quality is used. This actually results in the investment casting with outstanding reproduction details and chosen surface finishing. After drying, the process is again repeated with coarser refractories until the self-supporting mould or shell is made.