After the drywall is roughed in to the house, the seams and screws are “mudded”.  This process involves running joint compound, putty-like substance in-between all of the seams and over the blemishes and screw heads.   The joints have a paper tape placed over them for added rigidity and additional joint compound smoothed over it.  Corners use a light-weight and thin metal that is bonded with the compound as well.   Hundreds of pounds of joint compound as well as thousands of pounds of drywall board are used in the construction of a home.