I am taking some course on mastering watercolour where I find interesting references from inspirational master artists of the past. This blog post is a non comprehensive list of such artists with references to some of their work published online.
William Trost Richards - was an American painter who produced many acclaimed watercolour works of art in the 19th century.
James Abbott McNeill Whistler - Was an American painter of the gilded age of the end of 19th century. He worked primarily in the UK.
Charles Demuth - American painter who lived and worked in the first part of the 20th century. He worked primarily in watercolour. https://www.wikiwand.com/en/Charles_Demuth#Media/File:Demuth_Charles_Aucassiu_and_Nicolette_1921.jpg
Paul Klee - a Swiss impressionist artist from the early 20th century.
Andrew Wyeth - an American realist painter from the late 20th century.
Charles E. Burchfield - an American painter from the 20th century.