The Marriage and A Mirrorical Return (displayed nearby) are the latest additions to the Tate's considerable collection of Richard Hamilton's work. In the 1950s, Hamilton emerged as a key figure in what became known as Pop art, and he has remained an influential artist. Principally a painter, from the beginning of his career he has been an innovative printmaker, exploring a range of techniques, from etching to computer-manipulated imagery. These prints represent a breakthrough for him because they use a new technique that allows for both high quality digital printing and a lasting image. The Marriage developed from a faded print of a Japanese couple found by the artist. The image has been altered using a computerised paint-box which creates the effect of loose brushwork.