The palette knife is a spatula or trowel-shaped tool (approx. 15-20 cm long) with a flexible blade along its entire length that the painter uses to mix dyes on the palette and to apply paint to the canvas (1).
The spatula-shaped ones can be made of metal, wood or plastic and are also used to scrape off wet paint with the side of the blade without damaging the canvas.
The trowel-shaped ones have a metal blade whose shape and size (approx. 3-12 cm long; approx. 3-4 cm wide) vary greatly: it can be triangular, diamond-shaped, oval or rectangular - with or without rounded corners - attached to a straight handle. The latter are mainly used to apply small dots or wide stripes of paint to the canvas.
The palette knife with narrow, rectangular blade is also available as a pocket knife. Then it is a useful tool for testing colors.
The house painter also uses a larger spatula-shaped tempering knife, the blade of which is about 15-30 cm long, to mix paint. [MOT]
(1) With the advantage that new layers of paint can be applied over non-dry undercoats, without mixing with each other, unlike the brush (HEUNINCKX: 49).