How can you tell if paper is laminated or likely laminated?

• It often has a reflective sheen or glossy surface
• It is hard to tear without a lot of effort
• Drops of water bead on the laminated side
• The paper is meant for containing liquid (eg coffee cup)

Think your disposable coffee cup is all paper? Think again. Here's a photo of a coffee cup that has been in a compost bin for 1 year. Worms have eaten all the paper leaving the plastic layer behind.