Drywall tape is a building material used to cover seams that are common in the process of drywall construction. The tape makes it possible to achieve a perfectly smooth surface, giving the work a finished appearance that could not be achieved otherwise. Drywall materials of this type are available in plain paper as well as fiberglass versions.
For the most part, professionals prefer to work with the plain paper drywall tape. When used in conjunction with other drywall supplies, the tape itself will completely blend into the wall, making it impossible for even a trained eye to readily detect where the product was used to cover a gap or seam. Since the paper has a texture that is much like the texture of drywall panels, it is also very hard to locate the tape by touching the finished wall.
The basic process for applying plain paper drywall tape requires the use of a drywall compound that is often referred to as mud. A small amount of mud is spread into the seam or gap using a putty knife. Once the mud is in place, the blade of the knife is used to smooth the compound so that it is level with the surrounding wall. At this juncture, the drywall tape is applied to the seam or gap, then gently pressed until it adheres to the wall. Since a small amount of mud is likely to emerge on each side of the tape, the drywall professional will smooth the edges by gently using the knife to feather the mud away from the tape, leaving a smooth surface.
Drywall tape can also be used to seal corners where two sections of drywall meet. The process is essentially the same as covering seams or gaps. The one difference is that the section of tape is folded vertically before being pressed into the corner. This makes it possible to create a tight seal over the corner seam that is uniform and effectively hides the point where the panels join.
For the do it yourself homeowner, fiberglass drywall tape may be a better option. Drywall products of this type are sold in rolls and come with an adhesive backing, much like that of carpet tape. Instead of working with the mud, the homeowner can simply cut the section of tape needed to cover the gap or seam, remove the protective backing, and smooth the tape into position. It is still a good idea to use a drywall or putty knife to smooth the edges of the tape, making sure an airtight seal is created. Once the drywall panels are painted, it is very difficult to see where the fiberglass tape was applied.