The Mona Lisa

The Mona Lisa has been described as “the best known, the most visited, the most written about, the most sung about, the most parodied work of art in the world.” I could add “the most glazed” too. Leonardo used his famous “Sfumato” (literally smoky) technique to soften and blend edges with a milky glaze. That’s why there’s the enigmatic smile (on this and other Leonardos). You can’t quite pin it down.

Leonardo painted Mona Lisa, or should I say Lisa Gherardini (most likely anyway), in oil on a white Lombardy poplar panel. He started with a neutral gray or brown underpainting,  applying his colors in layer after layer of transparent glazes on top. It’s believed to have been painted between 1503 and 1517 – plenty of time for Leonardo to continuing fiddling with that smile. He was renowned for not completing paintings, or anything else for that matter. For some reason or another, it stayed with him in his studio and was never delivered.

The Mona Lisa is of course the most famous of all glazed paintings. When you peel away all the layers of mystique, parodies, bullet proof glass, years of yellowed varnish you get Lenonardo’s key technique: glazing.

As a footnote, the Mona Lisa was one of the first portraits to depict the sitter in front of an imaginary landscape and Leonardo was one of the first painters to use aerial perspective.  Behind her, a vast landscape recedes to strange surreal mountains. I have never looked at a Yes album cover the same way again (OK, I’m showing my age).

Glazing

Glazing is often sidelined as a painting technique, perhaps with a little mystique surrounding it. I use it fairly frequently and find it useful for integrating the paint surface, adjusting tone over a complete painting, or just in part:

Glazing demonstration in Acrylic

Glazing Demonstration in Oil

Here, I glazed just one bloom in a Still Life that I’d painted in oil.

 In acrylic, I would take a very similar approach, using a slow drying medium, or adding some retarder to my mix.

Glazing Tips:

1. Typically it’s best to position the canvas horizontally;
2. Use transparent pigments: Alizarin Crimson, Ultramarine Blue and Lemon Yellow are all good choices, mixed as needed to obtain the tint you are looking for;
3. With white I’d use the more transparent Zinc white over Titanium. Note that all whites will result in a milky Leonardo-style glaze, rather than a transparent glaze;
4. In acrylic, use a good quality fluid medium, especially for final finishes. A general purpose medium, diluted by say 30% water, works quite well in a pinch for passages in the middle of the painting process;
5. In oil, I’ve generally used linseed oil, sometimes lightly rubbing down any excess oil. Regardless, the result will be slow to dry (one week plus);
6. Tinted glazes are best completed with only a little paint in the mix, say 10 to 20%. Higher percentages of paint will quickly yield more opaque results even with transparent pigments;
7. For large areas use a large, soft, flat brush. I’ve glazed with a range of mid-priced synthetic brushes, typically 2″ wide. Don’t use a house paint brush, as although some are good quality, being thicker, they soak up all of your paint mix!
8. In acrylic, gently squeeze out most of the water from your brush prior to commencing glazing – wet brushes can momentarily add water into the process with very unpredictable results;
9. Get your mix on quickly, spreading it out in all directions. Then, carefully brush horizontally and vertically in succession with an even stroke, from edge to edge – almost dragging the brush horizontally. You can also use a soft rag in oil however don’t try this with acrylics;
10. Once you’ve achieved an even sheen (perhaps with some brush marks still visible), resist the temptation to over work. For the acrylic painters: should any part of the glaze start to dry…STOP!
11. Glazes look better dry than wet…give it time to dry before you inspect your work;
12. Practice first on a test surface to check out the effects!!

Exercises

1. On your next painting (perhaps following some initial layout), put the water pot, or solvent to the side of your work space and paint entirely using medium or oil rather than water or solvent. Notice that the paint flows better, blends more consistently and is generally more fun. Water and solvents are for clean-up!
2. Take an old painting or alternatively some swaths of paint on a flat surface and glaze with say 10% of a transparent pigment. Let it dry. Perform a second glaze with your mix over part of the surface.
3. Finally, try the same type of glaze with opaque pigment: Burnt sienna, Yellow Ochre, Cadmium (red or yellow) or Cerulean blue. Notice that the effect is less vibrant.

Acrylic Gels, Mediums and Additives

In the following video, I walk through the usage of acrylic mediums and additives:

 

Acrylic Gels and Mediums

Acrylic mediums are probably as misunderstood as they are useful. Think of them as clear paint. Acrylic medium is in effect, the “vehicle” that is carrying the pigment in all of your tubes of acrylic paint – only without the colour!

There is a dizzying variety of choices designed for various applications, from thick plaster-like modeling pastes and gels to fluid glazing and finishing mediums. The three most common uses are:

1. To add thickness for impasto effects: use Gel medium.
2. General painting – to help flow paint onto the canvas, marginally increase drying time and for better blending: use a general purpose painting medium.
3. Glazing and finishing – use a fluid medium, sometimes called “varnish”. Select matt or gloss to suit your preference.

There is a mind-blowing variety of names on store shelves – “gel fluid satin glazing paste” is about the only one I have not seen – yet! The good news is that most have a summary description on the bottle, speaking to the uses in the above general categories. The following website has a good summary: https://www.art-is-fun.com/acrylic-mediums

Slowing the drying time

A useful characteristic of all mediums is that they somewhat slow the drying time, essentially because they are adding more paint substance that then needs time to dry.  Retarder is an additive which further slows drying.

Retarder is not a Medium

“Retarder” (even more confusingly called ”Medium Retarder” in French) is not to be confused with Medium. Retarder is an additive as opposed to a painting material. Retarder works chemically in your paint mix (with or without medium) to slow down the drying time. I’d try painting without retarder and introduce it should you have drying problems. Even with retarder, drying can be unpredictable and the real solution is to choose a slow-drying series of paints.

Slow drying medium

In my view, more useful than retarder is to use a slow-drying acrylic medium. The Golden “OPEN” series is probably the best known.

Painting Oils and Oil Mediums

In the following video, I walk through the usage of painting oils:

Solvent free oils

I’ve pretty well evicted toxic solvents from my studio. In early stages, I might rub in a base with paint and linseed oil on a rag, later moderating the flow of paint with linseed too: I’ve got some very stiff paint that takes some (considerable) persuading to get out of the tube and additional oil is essential. Finally, I might use linseed oil for glazing, as above. Linseed oil is known to yellow over time and alternatives include walnut, poppy seed and safflower. Linseed has however been a mainstay throughout history and other oils may have other drawbacks: cracking being one, apparently.

Instead of solvent I use I use baby oil for brush cleaning. Following a painting session I wipe the brushes on newspaper and with paper towel, getting as much paint out as I can. Stiff brushes (which for me are the vast majority) then go head first into a tub of baby oil and stay there. Fine brushes are suspended (generally with bulldog clips) so that the tips do not curl up at the bottom. Some artists wipe out the baby oil and then store their brushes. This should also work well because the baby oil residue should not dry. 

At my next painting session, I just wipe and squeeze out as much baby oil as I can. At this stage, my brushes might not be 100% clean, so I will then look to see what remnants may be lurking in the bristles and allocate that brush to a color-compatible purpose. I will (very) occasionally refresh the baby oil. I do tend to paint quite thickly and any baby oil residue is inconsequential.

Don’t try painting with baby oil as it is non- drying..unless you like painting wet-on-wet for ever! Hmmm………….