Building Knowledge

Drywall Finishing Glossary: Key terms to know

Jan 23, 2023

Explore definitions of the most common terms related to drywall finishing materials, drywall finishing tools and drywall finishing application techniques


While hanging drywall is the first step to creating functional walls and ceilings, an equally important part of the installation process comes next: prepping the drywall for paint or wallpaper. This stage is called “drywall finishing.” The purpose of drywall finishing is to conceal fastener heads and joints between gypsum board panels to create a monolithic surface ready to receive final decoration.

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The following glossary defines the most common terms related to drywall finishing materials, drywall finishing tools and drywall finishing application techniques.

  • Beading or joint ridging: A linear projection or ridge in the center of the joint between two gypsum boards caused by expansion and contraction of the framing
  • Bed coat: The first coat of joint compound applied over the joints between sheets of drywall for tape embedment.
  • Block coat: The second coat of joint compound that’s applied on top of drywall tape.
  • Bond failure: A lack of adhesion between joint compound and the drywall panel.
  • Butt joint: Joints formed by short, non-tapered ends of a drywall panel.
  • Corner bead: A drywall trim that protects outside corners of the drywall against damage. It is attached after drywall is hung and before joint treatment begins.
  • Dry time: The length of time needed for the applied joint compound to dry between coats prior to final decoration.
  • Drywall Finishing Council: An organization committed to improving the quality and standards of the drywall finishing industry.
  • Drywall primer: A coating used to cover the entire drywall surface area to minimize the porosity differences between the drywall surface and joint compound prior to painting.
  • Finish coat: The last layer of drywall joint compound applied before priming and painting.
  • Inside corner: The intersection of two adjacent walls or a wall and ceiling to form a 90-degree corner.
  • Joint compound: The material used for taping and finishing drywall. Also called “drywall mud.”
  • Joint crowning: A problem that occurs at board joints when excessive amounts of joint compound are applied, or the joint treatment is not feathered out to the proper width.
  • Joint tape: Paper tape that conceals and reinforces drywall joints.
  • Levels of finish: Professional standards established by the Gypsum Association that break the process of finishing drywall into five distinct levels appropriate to how the wall will be used or decorated.
  • Mildew: A fungi growth (usually light, powdery and gray or white in color) that grows in moist and warm conditions and is most often found in wet areas, on paper, fabric and other surfaces.
  • Moisture protection: The ability of certain drywall panels — such as PURPLE XP® — to resist mold, mildew and moisture due to a specially-treated gypsum core and paper covering.
  • Mold: A fungi growth (usually thick and black, green, red or blue in color) that grows in moist and warm locations. All ProForm® products are engineered to resist mold and mildew growth.
  • Mud: Another name for joint compound.
  • Mud pan: A long pan specially designed for holding joint compound that accommodates a drywall taping or finishing knife for the application to walls and ceilings.
  • Nail pops: The protrusion of a nail, usually attributed to the shrinking of or use of improperly cured wood framing.
  • Outside corner: The intersection of two walls to form a 90-degree corner.
  • Photographing: A variation in color between drywall face paper and joint compound, creating a visual contrast.
  • Pole sander: A manual sander with a long, thin handle attached, which makes it ideal for sanding larger and harder-to-reach areas.
  • Ready mix: A type of joint compound that comes ready to use from the container and hardens by drying versus setting.
  • Sanding screen: A synthetic mesh version of sandpaper used for smoothing dried joint compound.
  • Sanding sponge: A material that is similar to sandpaper, but the abrasive material is attached directly to a synthetic foam sponge instead of a piece of paper.
  • Sandpaper: Paper covered on one side with abrasive materials used for smoothing surfaces.
  • Setting joint compound: A joint compound in powder form that chemically hardens when mixed with water used to treat joints and spot fastener heads in gypsum board installations.
  • Setting time: The time between mixing joint compound powder with water and the point at which it hardens.
  • Shrinkage: As joint compound dries, the water in it evaporates, which can cause thick applications to shrink and crack.
  • Skim coat: A thin coat of joint compound applied over the entire drywall surface to reduce imperfections.
  • Spray texture: The method of applying a non-aggregated drywall joint compound finish to a wall or ceiling to create a textured look.
  • Starved joint: A slight indent that forms along the joints between drywall panels due to a lack of joint compound.
  • Textured products: Joint compounds used to create a decorative surface texture on a wall or ceiling.
  • Working time: The maximum amount of time you have to work with drywall joint compound before it hardens.


  • Banjo: A tool used to apply the first coat of joint compound and drywall tape simultaneously to drywall joints.
  • Bazooka: A long-armed tool used to apply the first coat of joint compound and drywall tape simultaneously to drywall joints.
  • Finishing knife: A wide-blade tool used for applying and feathering the final coats of joint compound.
  • Mixing paddle: An attachment for power drills used to agitate and mix buckets of drywall joint compound before applying to the drywall panels.
  • Orbital sander: A lightweight, handheld sander used to smooth the dried joint compound.
  • Sander: A handheld power tool used to smooth joint compound by abrasion with sandpaper.
  • Taping knife: A smaller blade tool used for spreading the first coats of joint compound over nails, screws and drywall tape.
  • Trowel: A hand tool for applying smooth, thin coats of joint compound.

National Gypsum Company is the exclusive provider of high-performance drywall finishing products manufactured by ProForm® Finishing Products. From superior bonding to dependable set times, ProForm products deliver industry-leading performance to help you finish your most complex projects — all supported by best-in-class customer service.

Want to better understand how to finish drywall, the different levels of drywall finishing and what’s right for your project? Explore our Five Levels of Finish resource page to learn more or watch the How-To video.


National Gypsum Company is the exclusive service provider for products manufactured by Gold Bond Building Products, LLC, PermaBASE Building Products, LLC and ProForm Finishing Products, LLC.

The color Purple is a registered trademark of Gold Bond Building Products, LLC.