Valto Malmiola’s portrait of Sibelius, 1937. It was made with 30,000 so-called rules – strips of metal, often brass or type-cast metal, used for printing lines since the 1500’s.
More works by Valto Malmiola, made with the same technique, 1938-1943.
Images and info from Typographic Art of Valto Malmiola by Heikki Lotvonen, 2023. He mentions that for example Carl Fasol used this technique before Malmiola.