In the US you are allowed to create fake banknotes but there are some restrictions on how closely they can resemble real ones. According to the Counterfeit Dete

In the US you are allowed to create fake banknotes but there are some restrictions on how closely they can resemble real ones. According to the Counterfeit Detection Act of 1992, a reproduced bill must be: a.) either less than 75% or more than 150% the size of a real bill, b.) one-sided, and c.) made with only one color