How can you tell if Zig-Zag papers are fake?

Can you tell me how to identify if Zig-Zag papers are counterfeit? Is there a specific method or set of indicators that I should look for to ensure I'm not purchasing fake papers? Additionally, are there any common misconceptions or red herrings that I should be aware of when attempting to authenticate Zig-Zag papers? Your expertise in this area would be greatly appreciated.