One of the most powerful and beautiful techniques of oil painting is glazing. Instead of painting with thick opaque paint that is a certain final colour one builds up the colour and richness with multiple transparent layers of paint. The Old Masters used this technique extensively in their works and this results in the incredible glow and depth one sees when viewing one of their works.
There are many glazing mediums on the market that one can use to dilute paint to make oil glazes. They almost always have solvent in them so here are a number of methods I use to glaze without solvents.
Choose transparent pigments
In all these techniques it is very useful to use transparent or semi-transparent pigments. These colours have an incredible depth and richness to them and are perfect for using in glazes. Opaque pigments are harder to spread out to give a translucent effect. Check on the back of the paint tube for the paint’s transparency.
Paint straight from the tube
You can use paint straight from the tube and use your brush to spread it out thinly over the canvas. I find a big round or a strong bristle brush especially good for spreading. You can then use a blender brush to smooth out the thin layer of paint. Again, make sure you choose transparent pigments for this method.
Mixed with a little oil
You can use linseed or another drying oil such as walnut or stand oil to slightly dilute your paint to aid its spreadability. Don’t dilute the paint like you would with a solvent. A little oil goes a long way. You can either premix the oil in your paint pile or just dip the tip of your brush in a little oil before spreading some paint onto the canvas.
Into an oil couch
You can spread an extremely thin layer of oil over your canvas and then paint into it with paint straight from the tube. This aids in the spreading of the paint over the canvas. The key here is to have a very thin layer of oil. Spread the oil over the canvas then use a rag to lightly go over the whole canvas and wipe away the excess oil. Your canvas should feel slightly lubricated but you shouldn’t see any big patches of oil.
Walnut alkyd medium
Walnut alkyd medium is a nice solvent free medium that you can use to mix with your paint to aid spreadability in a glaze. It also enhances the gloss of each layer of paint adding more depth and richness to the painting.
Is there a “fat over lean” problem if you use Walnut alkyd medium in an early layer?
I’ve done a bit of research about this and as far as I can tell it is totally fine to paint as many layers as you wish over the top of each other as long as they have the same amount of oil content added. And this would be the same for walnut alkyd medium.
The main rule about “fat over lean” is to never do lean over fat. That is, never put more solvent in paint over a layer of paint with less solvent. Adding more oil to a paint layer makes it more flexible and slower to dry while more solvent makes it faster to dry but more brittle. So the main thing you want is the layers on top to be as flexible or more flexible as the layers beneath, as well as making sure they dry at the same speed or slower.
Because we are talking here about painting without solvents the rule is a bit more flexible – just make sure you either keep the amount of walnut alkyd medium the same in each layer or increase it.
I don’t think it would be a good idea to use a lot alkyd medium for the beginning layers to make them dry quicker and then use little or no medium on the subsequent layers. These layers would be slower drying and more brittle which could potentially lead to cracking problems in the future.
Pingback: Daniel Rigos : Smooth canvas for solvent free oil painting