impasto
Concise Oxford English Dictionary © 2008 Oxford University Press:
impasto /ɪmˈpastəʊ/
▶noun Art the process or technique of laying on paint or pigment thickly so that it stands out from a surface.
– origin C18: from Ital., from impastare, from im- ‘upon’ + pasta ‘a paste’.
'impasto' also found in these Oxford entries:

