Saturday Mac riddles 108

Here are this weekend’s riddles to entertain you through family time, shopping and recreation.

1: Etching, impression or papa for short. What am I?

2: An intangible shop selling only intangibles, excluding itself.

3: Here are plenty of keys but no lock, and they aren’t even in alphabetical order.

I will post the answers first thing on Monday morning.

Please don’t post your answers as comments here: it spoils it for others.