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.

One often starts an oil painting with a wash made from diluting oil paint with a solvent such as turpentine or using a lean painting medium. It is often useful to have a wash to block in the basic composition of the painting before applying thicker and more solid paint. If one wants to avoid using solvents you can use the following techniques when beginning a painting.

Alla prima
The simplest method is using the alla prima or all-at-once technique. The impressionists used this method a lot as one can see from their thick application of paint. All you do is use straight oil paint out of the tube and complete the painting in one sitting. Wet-on-wet painting and blending is fundamental to this technique.

Paint straight from the tube
If you don't need to start with a wash you can just use straight paint from the tube with no medium additives. There is no need to add anything to oil paint as its consistency straight out of the tube is fine to paint with. Just use your brush to spread and thin paint around the canvas. Transparent and semi-transparent pigments are useful when you want to have more of a translucent feel to your paint. Check the back of the tube of paint to check its transparency. If you wish to thin the paint even more you can use a medium such as walnut alkyd medium.

Acrylic underpainting
Oil paint adheres to acrylic paint so you can paint with oil paints over acrylic. Never paint the other way around with acrylic over oils as they will not adhere correctly to each other. You can start a painting with a thin acrylic wash and paint as many layers of acrylic as you want and then switch to oil paints for the subsequent layers of the painting. This has the advantage of the quick drying time of acrylics for the under layers when you are refining the composition whilst also keeping the intense luminosity and blending advantage of oils for the subsequent layers.

Water soluble oil paints
Whilst you can use water soluble oil paints for a whole painting to avoid solvents you can also just use them for the underpainting and use traditional oils and mediums for the subsequent layers. You can use water or a water soluble medium to thin the paint to create a wash just like you would with turpentine and then use a medium such as walnut alkyd medium with the traditional oil paints in the next layers.

Obsidian, oil on canvas, 40 x 30 cm

Omniscience, oil on canvas, 40 x 30 cm

Whilst oil painting without solvents I use the following techniques to clean brushes and my hands:

During Painting

Rag
A rag/cloth is incredibly useful with oil painting. Because oil paint dries so slowly you can clean most of the wet paint off your brush just by wiping the brush with a rag. This works especially well when changing between dark colours where slight colour intermixing isn't much of an issue. When changing from a dark colour to a light I will usually clean the brush with oil (see below). You can also use the rag to wipe wet paint off the canvas.

Brush Cleaner Jar

Holbein Brush Cleaner

I have two brush cleaner jars that have lids on them like the ones above. The sieve part in the bottom of the jar is extremely important. I fill them both up with linseed oil to cover the sieve. One is the 'clean' oil and one is the 'dirty' oil. When I have a brush that can't be fully cleaned with a rag I clean as much paint off with the rag and then swish it in the oil and push it against the sieve at the bottom of the jar. You can clean in the dirty oil first and then in the clean oil. You can completely clean a brush this way. Squeeze as much oil out of the brush against the edge of the jar then wipe it with your rag. You can now continue painting with a clean brush.

Final Cleanup

Oil Jar
One method I have been experimenting with for the past few months is first cleaning my brushes then just leaving them sitting in the clean oil jar. The brush bristles are completely covered in oil so they can't dry out. You can theoretically leave them there indefinitely. The beauty of this method is that I don't ever have to wash brushes in the sink (except for blending brushes which I need to have dry for the next use). It makes short painting sessions all the more enjoyable without the lengthy cleanup at the end.

One potential problem I have read about with this method is brushes bristles becoming swollen with oil that you can't ever fully get out. I haven't specifically noticed this problem but I can see how this could happen. I imagine this wouldn't happen to synthetic brushes though. I am tempted to still use this method even if this does happen as the brushes that I leave in oil are fine for painting wet in wet with oil paint. It may be a bit messy to have to clean them thoroughly for acrylic painting with water, but I'll just save some other brushes for that.

Soap and water
The other method I use to clean my brushes is soap and water. I have been using bars of vegetable soap that I buy in a health food shop but pretty much any soap should work. Just rub your brush into the soap and rinse through with water. You may need to do this a couple of times to fully clean the brush.

Dick Blick also sell a variety of brush cleaners and include a number of soaps such as the Masters Brush Cleaner. These work just like the bar of vegetable soap, which is usually cheaper.

I also use soap and water to clean my hands at the end of a painting session.