Reddit reviews Full-Color Fruit Crate Labels CD-ROM and Book (Dover Electronic Series)

Many are documented on the Bioshock wikia (some of which I've uploaded myself), but scattered across many pages.

Google Reverse Image Search helps somewhat. It appears that a lot of these are public domain and available in compilation books.

Otherwise, it's instinct and trying to find the appropriate keywords. I'm surprised how much work went into disguising the snowman as a pig, but retaining most of the features.

Here's another one from Burial at Sea.

"Stand Above the Crowd at Fontaine's"

Modiano Cigarette Paper


Concept Art of the Farmer's Market from the CultofRapture


Have One Oranges

I also found the Rapture City Archives to be really helpful in presenting all the ads in one place so I didn't have to extract the files directly.

I suspect that some of the cartoony ones are taken from 50s clip art books, but I'm not certain.