The Ambassadors (1533) by Hans Holbein the Younger, is perhaps the most famous work of anamorphic art. It hangs in the National Gallery in London and is best viewed from standing to the right of it. When it first came into the gallery’s possession, it took many years before the puzzle of the foreground “splodge” was solved.
Anamorphic art is also called slant art. It so strictly follows the rules of perspective that it can only be correctly viewed from one specific angle. This form of drawing and painting has made a fierce comeback as 3D drawings on the internet. These modern renditions of this eye trick are some of the most popular posts and reposts on social media. While the work might be impressive on a display it makes little sense when viewed directly. It is just a nonsensical splodge from every angle except the single intended viewpoint where the magic happens.
To create a drawing like this from hand is moderately difficult because the surface needs to have and maintain an extreme angle during the entire process. However, today there are tools that make this sort of drawing much easier, therefore the drawings have become amazingly complex. The use of photoshop to transform an object into an anamorphic image reference makes the process much less difficult and more fun. Every artist should try it at least once.