Here's a sample of his drawings from the book, done in ink, watercolor and gouache.
Done in wash and gouache over a pen-and-ink drawing, the landscape has the spontaneity of a first thought sketched from nature.
British Dictionary definitions for gouache
gouache
/ɡʊˈɑːʃ/
noun
1.
Also called body colour. a painting technique using opaque watercolour paint in which the pigments are bound with glue and the lighter tones contain white
2.
the paint used in this technique
3.
a painting done by this method
Word Origin
C19: from French, from Italian guazzo puddle, from Latin aquātiō a watering place, from aqua water
Word Origin and History for gouache
1882, from French gouache, from Italian guazzo "water color," originally "spray, pool," from Latin aquatio "watering, watering place," from aquatus, past participle of aquari "to bring water for drinking," from aqua (see aqua-).