Here are advices about my way of using the palette knife.
The exclusive use of palette knife is relatively recent and less widely than brush. At the begining palette knife was mainly used to mix colours on palettes. Learning to paint canvas with palette knife tasks longer than brush.
With this technique, oil paint becomes thick substance. The artist painter must have a more synthetic vision of its artwork, and he has to suggest what he paints rather than to show extacly what he sees.
Parameters that come into play, in my view, for the use of palette knives.
The knife pressure on the canvas.
The size of the palette knife.
The amount of oil paint you put on the palette knife.
The inclination of the palette knife.
The speed of the gesture.
The flexibility of the knife blade.
Wet-on-wet is my painting technique. This technique is also called by specialists ALLA PRIMA. So, when I begin a canvas I must finish it quickly.
I place a great value to the composition of my artworks.
The most significant difference is the effects of thickness we can get more easily with palette knives.
The second difference is the cleability of the palette knives. A simple wipe on the blades is enough to get them clean, while brushes are less easy to clean mainly with oil paint. So, with palette knifes the colours are always clean if due precautions are taken.
Another difference is the opportunity to mix the colours directly on the canvas, with that we can get surprising effects; see the picture above.
On the other hand the avantage of brush on palette knife is the easily to paint tiny details.
PALETTE KNIVES. Specialy configured to artwork, it is preferable to use different sizes. I use palette knifes with rounded corners. Those with sharp corners are inappropriate.
PALETTE. I use a white thin wooden board. Size 80cm by 55cm.
PAPER TOWELS. I use a lot of paper towels, the cleanliness of the blades is for me a prime means to got nice colours. With a palette knife that would not be clean, colours would be contamined, and the result will be muddy.
A GARBAGE BAG. For getting rid of the soiled paper and empty paint tubes.
I use large tubes, 200 or 225 ml. Pictures below show some samples of my usual colours. They are mixed with a small amount of white.