PURPLE: The color that changed everything

Jul 18, 2023

Setting the standard for moisture, mold and mildew resistance in drywall boards for 20 years


Few things are as unmistakable as a building project that uses PURPLE high-performance gypsum board. Inside or out, wet or dry, PURPLE delivers the confidence and peace of mind architects, builders and drywall contractors want when choosing the best gypsum board for their projects.

That’s because for over 20 years, Gold Bond Building Products, LLC, an affiliate of National Gypsum Company, has been innovating and evolving the PURPLE product line to make it the industry’s premier family of performance drywall products.

Top benefits of PURPLE high-performance drywall products

  • Inhibit mold and mildew growth
  • Resist moisture
  • Provide fire resistance
  • Enhanced acoustical quality
  • Offer superior durability

So, while the purple color may grab people’s attention at first, it’s what goes into each PURPLE product — from research and development to product innovation — that makes it the standard on commercial and residential job sites across the United States.

To fully appreciate the performance and functionality of today’s PURPLE product line, let’s look back at the challenges the industry faced, and the solution Gold Bond provided when it first introduced PURPLE to the world.

How addressing energy and climate issues created a mold problem

Energy and climate issues at the end of the millennium led to a renewed emphasis on energy-efficient construction. The government also recognized the need to address energy consumption and enacted stricter building codes and regulations.

Higher energy costs and updated building code standards concerning energy-efficiency required builders to tighten up their construction methods. As a result, construction designs started incorporating more insulation, double-glazed windows and other energy-saving features to reduce heat loss or gain, decreasing the need for heating and cooling.

While these new construction methods and code requirements were meant to help ensure buildings reduced overall energy consumption, they also created interior environments that were sealed so tight they trapped humidity. And high levels of indoor humidity led to an increase in mold issues.

So as one building issue — improved energy efficiency — was being addressed, another potential problem was on the rise within the walls of many structures.

When left unchecked, mold can have a significant impact on the building structure and its occupants.

  • Air quality: Mold and mildew release spores into the air, which can worsen indoor air quality and lead to respiratory issues and allergies.
  • Health issues: Mold and mildew growth in indoor environments can contribute to a range of health issues, including respiratory problems, allergies and asthma.
  • Repair costs: Mold and mildew issues often require professional remediation services, which can be time-consuming and costly.
  • Structural integrity: Mold and mildew can deteriorate organic materials such as wood and weaken the overall integrity of the structure.

As the focus on energy-efficient construction persisted into the late 1990s and early 2000s, many of these new, better-sealed buildings continued to experience cases of mold growth — often on the back of drywall panels and, subsequently, within the wall cavities. Therefore, the construction industry needed a reliable, mold-resistant drywall product to ensure healthier, more durable and more sustainable indoor environments.


Introducing the new color of confidence

In 2003, Gold Bond debuted the first PURPLE drywall product — PURPLE XP® — which promised “Xtra Protection” by offering the advantages of traditional moisture-resistant drywall with added mold and mildew resistance. This was achieved, in part, through the discovery by the company’s R&D team of a product developed in collaboration with a specialty chemicals company.

SPORGARD®, an antimicrobial formulation, had originally been created as a food preservative. However, through rigorous research and testing, Gold Bond identified that the same principles that allowed it to prevent food spoilage caused by microorganisms, including mold, could also be used to protect paper-faced gypsum boards.

After incorporating the extra mold-inhibiting properties of SPORGARD technology, PURPLE XP quickly took the building industry by storm, becoming the preferred, cost-effective solution for most interior commercial applications.

Building on the success of PURPLE XP, Gold Bond began to expand the PURPLE brand with new premium and specialty drywall products. This marked a wave of innovation at the company as it developed and launched a growing line of drywall products designed to solve a wide range of commercial building needs.

“When developing this new line of drywall products, we wanted to distinguish this family of moisture, mold and mildew resistant gypsum boards from the traditional ‘Green Board’, which was singularly moisture resistant,” said Jay Watt, director of marketing at National Gypsum. “We chose PURPLE as it was novel and noble, communicating the elevated performance of these new and innovative products.”

PURPLE Garage Ad

After years of growing its signature line of PURPLE drywall products, National Gypsum applied, and the U.S. Trademark Office granted National Gypsum a registration for the color PURPLE in 2012.

With PURPLE XP providing a reliable solution for commercial buildings, Gold Bond also began marketing the product for residential construction. The company’s Ask for PURPLE campaign helped introduce how the drywall’s moisture, mold and mildew resistance was designed to protect nearly every room in the house. Additional partnerships with HGTV, Today’s Homeowner and the DIY Network showcased the superior performance of PURPLE for both new residential construction and remodeling projects.


  • Features a gypsum core wrapped in mold-, mildew- and moisture-resistant, 100% recycled PURPLE paper on the face
  • Helps inhibit mold growth with the highest possible score on ASTM D3273 and ASTM G21 mold testing and less than 5% water absorption
  • Works for interior projects, including all wall and ceiling applications, as tile backer board in dry areas and in areas with limited water exposure, such as toilet/sink areas and above tile in tubs and showers
  • Offers a lightweight drywall board that scores and snaps easily, while GridMarX® installation guide marks on the board allow for faster and more accurate installation
  • Meets UL Classification for fire resistance and surface-burning characteristics

"When developing this new line of drywall products, we wanted to distinguish this family of moisture, mold and mildew resistant gypsum boards from the traditional ‘Green Board’, which was singularly moisture resistant. We chose PURPLE as it was novel and noble, communicating the elevated performance of these new and innovative products.”

Jay Watt


Jay Watt

Director of MarketingNational Gypsum Company

Versatility meets performance

Today, the PURPLE family of products offers the most comprehensive line of mold- and mildew-resistant drywall products. These innovative drywall products can also stand up to scratches, scuffs, dents and noise.

Whether you’re designing a project or installing the product in the field, PURPLE drywall products offer solutions that provide peace of mind.

XP® Gypsum Board features SPORGARD technology with extra mold-inhibiting properties, providing extra protection against mold and mildew compared to standard and fire-rated gypsum board products.

XP® Hi-Abuse® Gypsum Board features a heavy, abrasion-resistant face paper and a specially formulated core to provide greater resistance to surface abuse. As a result, the product delivers enhanced protection against scratches and scuffs in high-traffic areas, such as hallways, stairwells, corridors, lobby areas and entryways in both commercial and residential construction.

XP® Hi-Impact® Gypsum Board features the same qualities of Hi-Abuse board, yet with a fiberglass mesh embedded in the core to provide additional protection in areas prone to cavity penetration, such as gymnasiums, correctional facilities, schools and hospitals in commercial applications as well as play rooms and garages in residential applications.

All three XP gypsum products also have a specially-formulated core to meet fire-resistance ratings and can be used as a tile backer board in dry areas or areas with limited water exposure, such as toilet/sink areas and areas above tile in tubs and showers.

SoundBreak XP Wall® Board and SoundBreak XP Ceiling® Board both feature two pieces of high-density, mold-, mildew- and moisture-resistant gypsum board laminated together with a sound-damping, viscoelastic polymer. This innovative layer in between the two boards is engineered to keep unwanted sound where it belongs by reducing and dissipating noise — even between floors, SoundBreak XP Ceiling Board helps reduce sound transfer from structural noise caused by footsteps on the floor above.

SoundBreak XP Retrofit® Board is an acoustically enhanced, fire-resistance gypsum board for use in retrofit projects, allowing sound damping without demolition. Use SoundBreak XP Retrofit to improve the acoustical performance of an existing wall assembly and achieve a higher STC rating for existing interior gypsum board walls where sound transmission has become a concern.

Shaftliner XP® features a fire-resistant Type X gypsum core encased in a heavy moisture-, mold- and mildew-resistant, 100% recycled PURPLE paper on the front and back and sides. The panel is used to construct lightweight fire barriers for cavity shaftwalls and stairwells (1-4 hours) as well as area separation fire walls (2 hour) in townhouse and multifamily housing.


PURPLE eXP® is a technologically advanced fiberglass-faced gypsum panel that uses Sealed Surface Technology, making it ideal for constructing high-performing interior and exterior walls and ceilings.

eXP® Interior Extreme® Gypsum Panel features a fiberglass-coated facer that provides excellent weather and water resistance and comes with a 12-month exposure warranty, making it ideal for extreme mold resistant construction as well as prerock applications. Dimensionally stable under changes in temperature, all eXP panels resist warping, rippling and buckling.

eXP Interior Extreme® AR Gypsum Panel features a denser core and an enhanced coated glass mat for increased resistance to indentation and abrasion.

eXP Interior Extreme® IR Gypsum Panel is ideal for interior applications requiring increased resistance to wall cavity penetrations. The board consists of a dense gypsum core encased in a coated, specially designed fiberglass mat on the front, back and sides and a specially formulated fiberglass mesh embedded into the core for increased resistance to indentation and impact.

eXP® Shaftliner panels are key components in cavity shaftwall systems and area separation fire wall systems. eXP Shaftliner is a moisture and mold-resistant shaftliner panel with a fire-resistant (Type X) core used to construct lightweight fire barriers for cavity shaftwalls (1–4 hours) and area separation fire walls (2 hours).

eXP® Sheathing can be installed on exterior wall and soffit framing as a substrate for cladding. For both wood and metal construction, eXP Sheathing provides a solid substrate for various air- and water-resistive barriers and is a component in exterior insulation and finish systems.

eXP® Tile Backer is a substrate for tile applications in high-moisture areas, including showers, bathrooms, indoor swimming pools, laundry rooms and kitchens. It is also a code-compliant substrate for tile and other finishes in both wet and non-wet areas, areas of high humidity and in both standard and fire-rated assemblies (5/8" Fire-Shield Type X).

Explore PURPLE product resources and support.

For residential construction, the PURPLE materials calculator on our Ask For PURPLE website provides a customized list of the materials you need based on the size of each room. For commercial construction, download your free copy of The PURPLE Book® for a comprehensive list of detailed drawings and wall assemblies.

All customers have access to National Gypsum’s Excellence Across The Board® program, which provides industry-leading technical support and customer service. Need help specifying or constructing PURPLE products and systems? Reach out to your region’s National Gypsum construction design manager or the 1-800-NATIONAL® Construction Services team for answers and assistance.

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

SPORGARD® is a registered trademark of LANXESS Deutschland GmbH, Germany.