Art posters measuring 24x36 inches can make a great addition to any art collection. When purchasing an art poster, it's important to ensure that it comes with an original signature and a document stating that the artwork is authentic. Additionally, there should be a contract in place to prevent the resale of the artwork. This ensures that the poster remains a unique piece of art and retains its value over time. By purchasing an art poster with these guarantees, you can be confident that you are investing in a quality piece of art.