What does Type I or Type II indicate when referring to glues?

When discussing glues, Type I and Type II often refer to their water resistance properties, specifically in the context of how much exposure to moisture the adhesive can tolerate. Type I glues are waterproof, meaning they can withstand prolonged exposure to water without compromising their bond strength. This makes them suitable for outdoor applications or environments with high humidity. On the other hand, Type II glues offer some water resistance but are not fully waterproof, making them better suited for indoor applications where occasional moisture may be present.

While strength and finish grade compatibility are significant factors when choosing glues, the specific labeling of Type I and Type II is primarily associated with their ability to resist water, which is why option C is the correct answer. It is essential to consider the requirements of the project and the environmental conditions when selecting the appropriate glue type.