I had the opportunity to see a Julius Bissier watercolors and inks exhibition in the late 1980s in Mendrisio, Switzerland and I still remember it..
Julius Bissier was a German painter who moved to Ascona, Switzerland in the last year of his life in 1961 and so I happened to know his work at the little Art Museum exhibition in Mendrisio.
His work is to me very cheerful, graphical but with finesse. Obviously is not obsessed with realism. He tries to express something, he composes little watercolors with few elements. Some, like "Tamaro" (Mount Tamaro in Canton Ticino, Switzerland) or "Rondine" (swallow) are typical subjects of where I live although you don't recognize any of them in the paintings.
I like these delicate watercolors, the transparencies and the loose drawing in his work.
I don't much more about this artist, but I can see there is some influence of the Asian calligraphy in his watercolors.
Untitled, 1958, watercolor and ink on paper, 15.5 x 25.3 cm. (6 1/8 x 9 7/8 in.
Komposition, 1962, 15 x 24 cm ; Christies
Tamaro, 1961), 7¼ x 10 in. (18.4 x 25.4 cm.) ; Christies
Rondine, 1961,17 x 24 cm. (6¾ x 9½ in.) ; Christies
62.12.Sept By , 1962; Christies
Abstrakte Komposition, mixed tecnique,1962 18 x 23,5 cm ; Christies
A.6.April 64, 1964; Christies
Still Life, 1959, tempera and gold paint on linen; 7 1/2 x 9 3/4in. (19 x 24.6cm.) ; Christies
Composition, 1960, watercolor and ink
Untitled, 1964; Source
wiki (in German)