Gouache that I sometimes use on Tuesdays (when I go sketching with my pals). Someday I may make a concerted effort to learn how to use water media "properly". Nathan Fowkes sure knows how to use it!
("Gouache"!----I always have to look it up, because I never remember how to spell it).
Sketch: Celeste Bergin, Gouache tubes, Gouache & ink on 6x9 paper