What is Ben-Day dots?

Ben-Day dots are a printing technique using small colored dots to create shading and secondary colors in commercial printing. Named after illustrator Benjamin Henry Day Jr., the technique became ubiquitous in comic books, newspapers, and commercial printing. Pop artist Roy Lichtenstein famously incorporated visible Ben-Day dots into fine art paintings, highlighting the mechanical reproduction underlying popular imagery. While not specifically Surrealist, the technique interests artists working between pop culture and fine art, including many in the Pop Surrealism movement who reference comic book aesthetics.