Mykkänen started his design studies at the Central School of Applied Arts in Helsinki and graduated in 1951. He completed his education in Switzerland, where he worked as a commercial artist for the VSK organization. After coming back to Finland, Mykkänen worked as an illustrator for a Finnish magazine, before starting his freelance career in 1955. He designed for government departments and banks, and mainly made posters and book jackets. Mykkänen’s posters, logos and book covers have won several national and international prizes. Mykkänen received the Finnish State Design Prize in 1979. His major awards include gold medals at the 5th International Travel Poster Competition in Catania, Italy (1972); the Goldene Reisekutsche travel poster competition, Darmstadt (1973). He received the Czech Peace Council Award at the 12th Brno Biennial (1988). At the Warsaw Poster Biennale, Mykkänen was a chairman of the international jury in 1972 and a member of the international jury in 1986.