How Much do You Know about Masking for Powder Coating Applications?

I worked as a stripper after college.

(Author’s Note: The first rule for writing an article is to create a catchy first line or lede. Honestly, when I decided to write this article, that line popped so hard inside my head that I needed to sit down. The only thing that needs to be added is context. So, without further ado, here’s the context.)

After college, one of my first jobs was working at an Eau Claire commercial printing company in the plate room. In the mid-1990s, the printing process in the United States was much more labor-intensive than now.

Example of the 4-Color Printing Process
Example of the 4-Color Printing Process

Back then, several steps occurred before the printing machine began printing. Here’s an oversimplified description of the process.

  • In my case, the production department printed a positive for each color—Cyan, Magenta, Yellow, and Black. The best way to describe this is by printing this article. What comes out of your printer is a positive.
  • The pre-production department takes a picture of the positive, producing a negative (exactly like you find in pictures).
  • The printing plate results from burning the negative image to a thin aluminum sheet.
  • Techs attached the plate to a drum on the printing machine, turned it on, and Voila! Printed sheets!
Example of Masking
Example of Masking

The job of a stripper was to remove unwanted things in an image or document.

For example, look at the images on the right of the screen.

Let’s say the man timed things right to only show him and the monkey (Photo A) and didn’t want the image of the young girl included (Photo B).

A stripper would use tools to eliminate the girl’s image (Photo C).

Now, using AI, a graphic artist clicks a few buttons, and the power of Photoshop removes those unwanted artifacts.

Printing and powder coating are two completely different things. However, one thing they both share is masking.


Various materials such as tapes, plugs, and paper protect areas or parts of the object from the powder coating, properly coating only the desired areas and accomplished by powder coating masking, which is an essential step in the powder coating process—a free-flowing dry powder applied electrostatically and cured under heat to form a durable, corrosion-resistant finish.

Masking is an important step in the powder coating process, as it properly coats the desired areas and leaves any undesired areas untouched.

The Powder Coating Process

For any coating to be successful, both the coating and the coating process must meet the customer’s needs. Powder coating is no exception – successful coating depends heavily on the correct powder coating process. Powder coating uses an electrostatically charged powder applied to the coated object. The powder is then cured under heat to form a durable finish.

Powder coating is an electrostatic coating, meaning that electromagnetic forces create the coating. The powder coating process starts with the creation of a coating solution. This coating solution is then electrostatically charged, causing it to attract the powder. Because of the electrostatic properties of powders, the powder coats the coating, then cured to form a durable finish.

What is Powder Coating Masking?

Masking is an important step in the powder coating process because it protects areas or parts of the object from the powder coating, allowing only the desired areas to be properly coated using masking materials such as tapes, plugs, and paper.

Types of Masking Materials

Plugs and caps for use in masking while powder coating is taking place
Various materials for masking

Most powder coating plants have a variety of masking materials that employees can use to protect parts of the coating line from the coating process. The most common masking materials are heat resistance tapes, film masking paper, and plugs. Heat resistance tape is a coated paper made with a heat-resistant material, and film masking paper has a layer of heat-resistant paper. This paper protects areas with a coating that creates a printable image on paper, such as notepads and labels. Film masking paper is usually available in 3 mils (0.003”) or 5 mils (0.005”) thicknesses.

Selecting the Right Material

It is important to choose a masking material that is resistant to hot coating conditions and provides some protection against the coating powder itself.

The coating finish determines the masking materials. Common coating finishes include metal, paint, and a clear coat.

Temperatures play a part in masking, too. The line carrying components through a curing oven exposes the substrate to different temperatures based on predetermined specifications.


While powder coating is durable, it’s susceptible to wear and tear, especially in high-use areas, because it’s applied as a dry powder, not a coating. Despite a powder coat, wear and tear damage certain parts, while others remain unaffected.

Masking protects those areas and ensures even the application of the object’s surface. If a coating application has uneven wear and tear, the coating on the rest of the object may also have uneven wear and tear, resulting in a damaged finish.

Places Needing a Mask

There are several areas of a metal substrate that powder shouldn’t cover, including:

  • Seams and joints
  • Areas where the powder coating may cause a weak bond
  • Areas where the powder coating may flake off
  • Areas with thin or uneven surfaces
  • Areas prone to corrosion or oxidation


Masking tape for powder coating applications

There are a few different techniques available when masking a powder coating application. Each technique has advantages and disadvantages, so it is important to choose the correct one for the correct application. The type of masking material used and the coating application are the most important factors when masking a coating application. Here are a few coating masking techniques:

  • Plug and paper: a plug and masking paper covers the applicable area, then the coating is applied, then removed after leaving the curing ovens.
  • Prescribing: When provided with a prescription, powder coating is applied to the object, protecting the desired areas of the object.
  • Simple plug and paper: A simple plug and masking paper masking technique uses a plug to seal the coating application and a masking paper to protect the coating application, which is the simplest masking technique, making it suitable for low-risk coating applications.

In Sum

While it may be easy to spray powder over an entire substrate for protection, there are several examples where it may cause more problems than solutions. Masking creates a protective barrier between the electrostatic powder and the metal substrate, eliminating any possible problems before they happen.

Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Skip to content