For any paint work, the substructure operation must be performed, the substructure means that all the holes and cracks and generally the recesses or protrusions of the work surface should be covered so that when the paint is applied on the work surface, it is smooth and even. Is coming. Eliminating these indentations and protrusions and obtaining a smooth surface is called substructure, which uses putty for this purpose, therefore, this process is called putty work, which requires tools to do it. Putty is a special work.