Salad bags, potato chip bags, tea wrappers, all have to be printed and I work for a company that does them all. Ink, several types of solvents, glue and plastic combining at 400-1000 feet per minute in a warehouse kept at a negative pressure to keep the flammable fumes inside. Hard work, long days(12 hour shifts), and a lot of scrubbing to do before you're clean enough to go home. All in all a facinating process that most people don't even think about.