What is a painting knife?
A painting knife is a knife that has a pointed tip and a flexible steel blade. The blade can come in a variety of different shapes and sizes. For example, it can be in the shape of a rectangle, a triangle or even a diamond. The main part of the blade is lowered from the wooden handle like a trowel. This is to prevent the artist’s hand from coming into direct contact with the paint on the canvas. Painting knives look a lot like metal spatulas.
So why do artists use painting knives?
Painting knives are mainly used for applying paint on to a canvas. Because they come in different shapes and sizes, a variety of different effects can be produced. Using a shorter blade can create angular strokes, while using a longer blade makes it easier to put down a long stroke of colour in one go. Painting knives can also be used instead of a brush and are useful for adding texture to a painting. Using a painting knife to apply paint is similar to buttering a piece of bread.
Isn’t it the same as a palette knife?
The two are often confused because they are very similar. Palette knives have a flexible, blunt blade that’s straight and wide with a rounded edge. Palette knives are more suited to mixing oil and acrylic paints on a palette, hence their name. Many people do refer to painting knives as palette knives and vice versa, even though they are different.
How do I use one?
Scrape the knife across the surface of the paint, as if you were getting butter or jam on to a knife. Hold the handle firmly with a tight grip and use your wrist if you want to change the angle of the knife in relation to the canvas. The simply apply the paint like you would apply butter or jam to some bread. It’s that easy, even though it is a bit different from using an ordinary brush. There are a few different techniques that can be used for extra effects.
Different effects
You can produce very thin lines of colour by dipping the knife edge into some paint then gently tapping the knife on to the canvas. Or you can spread the paint around as if it were butter, smearing it on to the canvas. This way you can have a completely flat texture. If you want ridges in your paint, simply life your knife up from the surface of the paint as you go along. You can even use the tip of the blade to scratch into wet paint, creating a variety of different effects; the sharper the knife’s edge, the finer the line will be. You can even alternate the pressure as you apply the paint, creating different effects in a single go.
What paints can be used?
The good thing about painting knives is that they can be used with any types of paint, even watercolours. You’ll get better effects if you use a paint that is quite consistent and retains its form, as well as any marks you make with the knife. A handy hint for using acrylics is to add a bit of modelling paste so the paint will be a bit thicker. Beware that some additives can affect how long it takes paints to dry. Additives can help retain imprints and add to the overall consistency of the paint.
Experiment
This article has given an overview of painting knives and some ideas as to what they’re used for and how to use them. If you’ve always painting with brushes and fancy trying something different, go for a painting knife. Experiment with different paints, colours and techniques. Learn how the knife can add different effects to your painting and implement these into your next work to add texture and depth.