I'm looking for a *descriptive* word to use when referring to *something that is public*.

It's better if I give an example:

Consider the adjective *red*. When something is *red* you could say it shows some *redness*.

The same thing with *public*, but I'm not sure if *publicness* is a word, and even if it is it just sounds weird.

Edit: Just found out that this class of words are called abstract nouns.