Painting with a knife is a bit like putting butter or jam on bread and produces quite a different result to a brush. Painting knives are excellent for producing textured, impasto work and sweeping areas of flat color as well as tiny shapes of color.
The range of marks you can produce when painting with a knife rather than a brush is quite varied, and can produce beautiful effects. This list is an introduction to the possibilities.
The trick of palette knife is to hold the handle very lightly. The harder you press, the more the paint will ‘smear’ and become dirty. To keep your colours clean you need to work very lightly.
Sgraffito is just scratching into wet paint. A knife with a sharp point will give a narrow line, but any shape of knife can be used.