Acrylic resurfacer is needed to prepare and level surfaces, particularly for tennis courts and other sports surfaces, by filling voids, creating a textured base for better adhesion of subsequent coatings, and hiding minor repairs.  

Here's a more detailed explanation: Surface Preparation: Acrylic resurfacer acts as a base coat, filling in voids, cracks, and uneven spots on the pavement (asphalt or concrete).  

Improved Adhesion: It provides a textured surface that allows subsequent color coatings and other materials to adhere properly, ensuring a durable and long-lasting finish.  

Hiding Imperfections: Acrylic resurfacer can cover minor surface blemishes and repairs, creating a smoother and more uniform playing surface.  

Even Application: It helps ensure consistent application of color coatings and other materials, preventing uneven or patchy results.  

Long-Term Durability: By preparing the surface and promoting good adhesion, acrylic resurfacer contributes to the overall durability and longevity of the sports surface.  

Example: Think of it like priming a wall before painting – the primer (resurfacer) provides a good base for the paint (color coatings) to stick to and create a smooth, even finish.