unnoticeableness

/ʌnˈnoʊtɪsəbəlnəs/
noun
  1. The quality or state of being difficult or impossible to notice; lack of visibility or attention.
    • Her quiet manner and plain clothes contributed to her general unnoticeableness in a crowd.
    • The unnoticeableness of the small crack in the vase made it easy to miss during the inspection.
    • The designer aimed for the unnoticeableness of the security camera so it wouldn't distract visitors.