This unique work, rare on the art market, presents the Hungarian artist Victor Vasarely as a pioneer of op art and geometric abstraction. Already during his graphic design studies and immediately after them, he dealt with the expressive possibilities of geometry and used a reduction of shapes also as a creator of advertising materials for the pharmaceutical industry. In op art, pure geometric shapes create the illusion of space and movement, referring to Renaissance trompe l'oeil (the pursuit of maximum illusion on a two-dimensional background). He also grew fond of the medium of graphics, which represented a way to democratise art for him. A similar artistic development can be seen, for example, in Andy Warhol, twenty-two years younger, who immigrated to the USA with his family, learned graphic design and found a job in advertising to eventually become an icon of graphic art, especially pop art. Vasarely chose strange titles for his works not based on anything real. He often chose a random grouping of letters and paid attention to their euphony so that the title corresponded to the atmosphere or content of the work. BERC-Z comes from his mature period of work and a period of great honours – in 1965, Vasarely was called the “father of op art” at an exhibition in New York’s MoMA, and five years later he was preparing his first retrospective exhibition. This painting is part of a free cycle in which he developed straight horizontal or vertical lines in which an invisible thorn seemed to penetrate vertically into their centre and deform these lines. The presented painting differs from the others in the series by its pleasant colours and the gentle blending of blue and green shades with black and white. The result is a visually striking and utterly immersive work whose value enhanced its presentation at Christie’s, London, in 2022. It is listed in the artist’s inventory under No. 1402. Presented in the original framing. The artist’s inscription with title, date, and signature on the reverse. Assessed during consultations by PhDr. K. Srp and M. Vasarely. Attached is the expertise of PhDr. J. Machalický and the Fondation Michèle Vasarely certificate.