Solution: Something that fades into the background - NYT Crossword

I am not entirely sure of the intended meaning of this entry. [Something that fades into the background] solves to WATERMARK, a sort of label that indicates something’s provenance so that someone else can’t claim it. These were embedded in paper at printing presses centuries ago and are now hidden in the metadata of all kinds of digital media. Even when they’re visible, they are usually translucent or faint. This could be what’s meant by “fading,” as the clue says, but I also wondered whether the WATERMARK in question might be a mark left by a glass sweating on a coffee table, which usually does disappear over time.