Which statement about lightweight fillers is true?

Lightweight fillers have indeed improved in performance over the years, making them a popular choice in collision repair and refinishing. These fillers are designed to provide excellent adhesion, smooth finish, and easy sandability, which are crucial for achieving high-quality repairs. The advancements in materials and formulations have led to lightweight fillers that not only reduce the overall weight of a vehicle but also enhance the durability and effectiveness of repairs.

Improvements in their performance can include better moisture resistance, improved compatibility with various substrates, and enhanced resistance to cracking and shrinking. These properties ensure that the filler can effectively bridge gaps and imperfections in the bodywork, leading to a better finish and longer-lasting repairs.

The other statements about lightweight fillers—suggesting a decrease in effectiveness, becoming heavier, or requiring mixing with metals—do not accurately reflect the advancements made in filling technologies. Therefore, the statement regarding the improvement in performance is accurate and aligns with industry trends.