Which factor can contribute to the occurrence of checking?

Checking refers to fine cracks that develop in a dried paint film, which can be influenced by several factors involved in the application and curing process. One major contributor to the occurrence of checking is not allowing adequate flash time between coats. Flash time is the period that allows the solvents in the base layer of paint to evaporate before applying additional layers. If this time is not respected, the solvents trapped beneath the newly applied coat can create pressure and lead to surface cracking. This pressure builds as the underlying solvents evaporate, ultimately resulting in a compromised paint finish.

While using a primer is essential for proper adhesion and surface preparation, and water-based paints have their own specific drying characteristics, neither directly contributes to the checking phenomenon in the same manner that insufficient flash time does. Similarly, applying paint too quickly can lead to other application issues, like runs or sags, but it is not the primary cause of checking compared to inadequate flash time between coats. Understanding the chemical interactions and physical properties of paint during the drying and curing stages is vital for preventing issues like checking.