Spanish artist Pablo S. Herrero. He’s quite well known for his large-scale murals on and in buildings, but I just love love love these ink on paper pieces.
poul gernes artist - Google Search
Untitled (Target Paintings) by Poul Gernes (1966-1969)
Allen Ruppersberg Preview Suite prints, set of ten color posters with text
Colorama Paradise - Manuel Fernández
BG Paintings - Manuel Fernández
Joan Saló. Untitled pen on canvas 200x200 cm. 2010