This illusion – named Pinna's Illusory Intertwining Effect – first appeared in Shifts of Edges and Deformations of Patterns ...

This custom cutting board, crafted from walnut and maple, measures 18" x 21" x 2" and weighs nearly 20 lbs (9 kg). The pattern is originally from @mtmwood, who offers plans for a smaller 13"x13" ...

For less terrifying optical illusion murals see these brilliant artworks made with a spray can. And if you want to continue ...