Which factor is NOT considered when assessing an object's ability to be cleaned?

When assessing an object's ability to be cleaned, the object's historical significance is not a factor that impacts its cleanability. The primary focus in this assessment is on the physical characteristics and condition of the object itself, as these directly influence how contaminants can be removed.

For instance, an object's porosity is crucial because porous materials can absorb contaminants, making them more difficult to clean. Similarly, the condition of the object, whether damaged or intact, can affect the methods and products used in the cleaning process. Lastly, understanding the type of surface contaminants present is essential as different contaminants may require specific cleaning techniques or agents.

In contrast, an object's historical significance may inform decisions around preservation or restoration but does not affect the fundamental ability to clean the item effectively. Thus, while it is an important consideration in wider conservation practices, it is not relevant to the immediate capabilities of cleaning the object.