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A neighbour of mine has one wall in their house papered like this. Every time a new guest comes in, they are asked to colour-in a character and initial it (more pics in comments).(r/pics)
For anyone interested I believe I found the wallpaper on amazon www.amazon.com/Burger-1-Piece-Standard-Colour-Wall…
edit – here’s a link to main site if for whatever reason you would rather not use amazon