Which of the following could be a substrate in a coating system?

Which of the following could be a substrate in a coating system?

• A. Wood
• B. Sunlight
• C. Air
• D. Noise

Answer: (A)

In a coating system, the substrate is the base material that receives the coating film. It provides the surface for adhesion and determines how the finish will perform. Wood fits as a substrate because it is a solid material that coatings like primers, sealers, and topcoats can adhere to and protect. The other options aren’t substrates: sunlight is energy, air is a gaseous medium, and noise is sound—none are surfaces that can receive or bond with a coating. Wood’s properties—such as porosity, moisture content, and potential tannin bleed—also influence surface preparation needs, like cleaning, sanding, and priming, to ensure good adhesion and film formation.

In a coating system, the substrate is the base material that receives the coating film. It provides the surface for adhesion and determines how the finish will perform. Wood fits as a substrate because it is a solid material that coatings like primers, sealers, and topcoats can adhere to and protect. The other options aren’t substrates: sunlight is energy, air is a gaseous medium, and noise is sound—none are surfaces that can receive or bond with a coating. Wood’s properties—such as porosity, moisture content, and potential tannin bleed—also influence surface preparation needs, like cleaning, sanding, and priming, to ensure good adhesion and film formation.