Paper-thin is an idiom that may not be as old as you think. We will examine the meaning of the idiom paper-thin, where it came from, and some examples of its idiomatic usage in sentences.
Paper-thin means extremely thin, something that is cut in a very thin slice. For instance, a sandwich may contain meat or cheese that is sliced paper-thin; a cheap hotel may have walls that are paper-thin. Paper-thin is also used figuratively to mean a premise or excuse that doesn’t hold up to scrutiny. The expression paper-thin didn’t really gain traction until the 1920s or so, which is interesting. Paper has been around much longer, but perhaps the public’s access to very thin paper was limited before that time. The word paper-thin is always hyphenated when used as an adjective before a noun; it is usually hyphenated when it is used after a verb, though it may be seen without the hyphen. Paper-thin is a compound word, which is a word that is derived from two separate words joined together.
The cloak is “paper-thin and inexpensive,” according to a release. (The Deseret News)
It’s a shame her stage had to be shared with two paper-thin male characters. (The Straits Times)
You may notice that I advise that you cut the potato slices paper thin and this is because it allows the potatoes to cook through faster. (The South African)