The job of patching a ceiling requires the use of plaster, which is a material made from lime and sand that is used to create a smooth surface. Plastering is a process of applying the material to the ceiling in order to fill in any cracks or holes and create a level surface. Once the plaster has been applied, it must be allowed to dry before any painting or other finishing work can be done. Patching a ceiling with plaster is a time-consuming task, but it is necessary in order to ensure that the ceiling looks its best.