Born and died in Zagreb, Svečnjak is considered as one of the most important Croatian painters. He enrolled the Art Academy in 1927 first in the sculpture department under the guidance of Ivan Mestrovic, Rudolf Vladec and Ivo Kerdic. In this period, he accepts the Mаrxistic teaching and becomes an active member of the Communist Party. This political activity brought him in conflict with the authorities and he was repeatedly arrested. In 1929 he moved to the Painting department in the class of Vladimir Becich, Tomislav Krizman, etc. Until 1933 he continues with his leftist political activities. In 1933 he makes a study trip to Paris where he becomes a close friend of Miroslav Krleza. During the Second World War, he was a partisan activist and he was hiding from the Nazis. In 1943 he was convicted to death from the Nazis and he hides in Italy. After the war, he becomes a prominent Yugoslav painter and organizes exhibitions all around Europe.
Svečnjak visited Macedonia after the liberation, around 1948 where he painted the oil paintings: “Skopje” and “Samoil Fortress in Ohrid” which are today in the art collection of Strossmajer Gallery of Old Masters in Zagreb.