Monday Morning Art School: fat over lean, what does it mean?

Mastering fat-over-lean will remove the need for varnishing and ensure a long life for your paintings.

Ottawa House, oil on canvas, available, is going in my gallery this summer.

There are three fundamental truths of oil painting, which are:

• Big shapes to small shapes
• Darks to lights
• Fat over lean

The first one is more about how to think than about the technical aspects of oil paint. The second is a response to white paint’s infinite ability to dilute darker shades. The third is really the most difficult one to master, and the one that has long-term archival implications.

Belfast Harbor, oil on canvas, available, is also going in my gallery this summer.

The business of laying down paint is a craft, one that’s been developed over millennia. It’s possible to take this craft to new places, but only on a firm foundation of technique. That doesn’t mean that things don’t change; if they didn’t, we’d all be still painting encaustic funerary portraits a la the Romans. But there is still broad consensus on how oil paint is applied.

Fat-over-lean developed to prevent two problems: sinking color and cracking paint emulsion. The first is that dullish grey film that develops over paint that’s overthinned with solvent. Cracking paint doesn’t usually appear until after the artist is dead but is a major issue in some masterpieces.

Some manufacturers of alkyd mediums argue that the fat-over-lean rule no longer applies. I take this with a grain of salt. It’s a familiar argument to conservators now trying to fix 20^th century masterpieces that were painted with zinc oxide, once considered a great substitute for lead white. It takes time for problems to appear in paintings, time that’s measured in decades, not years.

Owl's Head, 11X14, oil on canvas, available.

Fat over lean sounds simple, but the application is tricky. By ‘fat’ we mean the medium—either commercially-mixed mediums or drying oils like linseed, poppy or walnut. Remember that the paint itself contains some of this medium as a binder, usually in the form of linseed oil. By ‘lean’ we mean the pigment and a solvent, usually odorless mineral spirits (OMS), or, if there are unreconstructed traditionalists out there, turpentine.

The usual way to achieve this is by cutting the initial underpainting layer with OMS. Since it evaporates, it leaves a thin layer of paint on the surface. As you develop additional layers, increase the amount of paint and, ultimately, medium.

Drying oils don’t evaporate, they oxidize. That means they stay there, bonded with oxygen, creating a new chemical structure on the surface of the paint. This can be extremely durable, when done on a proper lean base.

In plein air, this process is usually cut back to two or three steps: an underpainting cut with OMS, a layer that’s pure paint, and then possibly a detail layer cut with medium on the top. However, in more complex paintings with more layers, the shift from lean to fat can be more gradual.

Vineyard, 30X40, oil on canvas, available. In larger works, the shift from lean to fat is more gradual.

Either way, you want the bottom layers to have more OMS and less oil and the top layers to have more oil and, hopefully, no OMS at all.

Another way to get there—less accepted—is to use only painting medium, starting with almost none in the bottom layers and building more and more oil into the layers as you develop the painting. However, the vast majority of painters start with thin underpainting as a means of sorting out their ideas. For them, there’s little advantage to this method.

Many painters never use medium at all. I use very little myself. I like Grumbacher’s traditional oil painting mediums (labeled I, II, and III), but the looser my method has become, the less I use at all. It’s almost always just refined linseed oil, since I can fly with it.

Monday Morning Art School: that sinking feeling

Over time, the dark passages in an oil painting can grow hazy. In watercolors, the beautiful, jewel tone on the palette can look flat and dull after the paper dries. That’s ‘sinking’ color, and an ounce of prevention beats a pound of cure.

Clear Morning on Bunker Hill, 24X36, $3985 framed.

Oil painting: Sinking is caused by the displacement of the oil in the top layer. It’s most obvious in dark passages, but that’s only because the dusty haze is most visible there. It appears slowly over time—a painting that was once exuberantly colorful is suddenly dull. The different drying times of pigments means that color will sink unevenly across the canvas, giving it an irregular, blotchy look. Details that were once subtly beautiful will disappear.

Sinking can be repaired by oiling out or varnishing, but this may need to be repeated to keep the painting beautiful. If a painting is sold, you have no idea if it’s losing its color. It’s far better to do it right in the first place.

Tom Sawyer's Fence, 14X18, $1275 unframed.

Sinking has three common causes:

Too much solvent—the painter has not mastered the art of using unadulterated paint or painting mediums in the top layer. He relies too much on odorless mineral spirit (OMS) to get good flow. The OMS takes the place of the linseed oil binder and then evaporates. That leaves the pigment particles isolated, with no oil surround. Air doesn’t have the same refractive index as linseed oil, so a pigment that looks dark and beautiful in solution looks dull and grey when the binder disappears.

Not enough oil in the top layer of paint—this is why we keep repeating that old saw, ‘fat over lean.’ There’s enough oil in modern paints to make a solid top layer, but only if applied in proper thickness. If you want to paint thin, you must cut your paint not with OMS but with an oil-based medium.

Over-absorbent grounds—acrylic gesso is more absorbent than oil gesso, but a well-prepared acrylic ground is fine. However, a very inexpensive board may not have enough ground to stop oil from seeping through. An aftermarket coating of gesso is a good cure. Non-traditional grounds like paper and raw fabric need very careful preparation.

Bunker Hill overlook, full sheet watercolor, available. One of the advantages of Yupo is that there is no sinking.

Watercolor: “The difficulty in watercolors is not that it is ‘unforgiving’, as amateurs widely misbelieve: it is that it begs for fussing,” wrote Bruce MacEvoy. That fussing takes the form of overworking passages. Alla prima, or ‘on the first strike’ is vital in watercolor.

We want the pigments to stay on the top of the paper, rather than sink into it where they can’t be seen. The cellulose fibers of watercolor paper were laid down in a stiff mat so that pigments will sit nicely on top. Reworking wet-on-wet, scrubbing, and other repairs cause the fibers to unravel, creating a microscopic forest of random threads. Paint sinks into its crevices. The color is duller and, worse, blotchy.

The deck of American Eagle, from my sketchbook from Age of Sail workshop. 

Most watercolor paper is coated with gelatin or other sizing. This controls its absorption of paint. When you do a preliminary wash of color, you’re wetting the paper along with establishing primary shapes. If this wash layer is allowed to dry completely before the next layer is applied, the water and paint mix with the sizing and create a new layer, comprised of binder, sizing and pigment. That new, dense sizing layer can help hold successive layers of paint on the surface.

But if you ‘lick’ the wet paper constantly with your brush in an attempt to control minor flaws, you interrupt this process. Unless the paper dries completely between approaches, each pass with the brush lifts more paper fibers. That disturbance increases the capillary action that draws the pigment deeper into the paper. Overworked passages look dull and fuzzy.

Of course, the type and quality of the paper you use matters. Hot press paper is more tightly-compacted, making it more tolerant of overbrushing. Cold-press paper has less sizing and looser fibers. It tolerates less fussing.

What you can and can’t change

Thought and practice moves our painting style, but it’s incremental, just like the Mary Day docking.

Winch (American Eagle), oil on canvasboard, by Carol L. Douglas, 12X16, $1449 framed.

Windjammers are slippery little devils. I should know that by now. You think you understand the rhythm of their comings and goings and you find one or two likely candidates and commit to painting them. Then you look away for a moment and you find a subject slipping away from her berth, heading out to sea.

That happened to me on Monday, when I’d stopped to paint before my dentist appointment. (‘Quickie’ has an entirely different meaning to artists than to the rest of the world.) I’d limned in the ketch Angelique, and the light and shadows were notated, but as I sadly watched her slide out of her berth, I knew she wouldn’t be back for days.

“You didn’t take a photo, did you?” asked Ken DeWaard. He knows most of my bad habits, thanks to my friend Terry spilling the beans. I could almost paint Angelique from memory, but that never ends well. I shook my head ruefully, and begged him for a picture. “I’m just enabling you,” he muttered, but he sent it to me anyway.

Lobster fleet at Eastport, oil on canvas, 24x30, $3478 framed.

There was still the fine flat transom of the Lewis R. French to paint. She celebrated her 150^th birthday this year, and that’s something to celebrate. We both set to again, but not five minutes later, Mary Day hove into view. She was heading for the berth directly in front of us. Normally, that would be a good thing, but it would obliterate the rest of our view.

Mary Day doesn’t have an engine; she’s pushed into place by a tender. It’s fascinating to watch 90’ of wood and sails delicately slide into her berth, guided by a tiny gnat of a boat. Since our subjects had vanished into the rhythm of a working harbor, we had no choice but to sit back and enjoy the spectacle. We talked about color and mark-making.

Striping (Heritage), oil on canvasboard, 6X8, $435 framed.

I hold that mark-making is as personal as handwriting. Once you’ve taught someone how to form their letters, you have very little control over the finished product. I’m shocked, sometimes, to see how much my handwriting resembles my mother’s. That’s a real mystery, since I’m a lefty and she was right-handed.

As a teacher, I do influence my students’ marks. “Don’t dab!” I’m wont to say, although I’m well aware that Pierre Bonnard dabbed to great effect. He’s the exception that proves the rule. Dabbing, in the hands of beginners, looks amateurish.

Mostly, I ask them to experiment with all the different things a brush can do and then find their own ways of using them. Once they’ve found that place, it’s pointless to try to shake it up too much. (This is why I don’t encourage palette-knife painting in my classes; it short-circuits this process.)

Pleasure boats, oil on canvasboard, 12X16, $1159 unframed. Even though this is not 'my style', it's still one of my favorite paintings.

“There are things that are immutable, and it’s pointless to try to change them,” I said to Ken as we watched Mary Day’s crew work. “For example, I can’t be 6’5” and you can’t have my curly hair.”

“But there are things you can change,” said Ken. He’s right, of course. Our choices of brushes, canvas and pigments all influence our paint application, just as choosing a gel pen makes us write differently than with a pencil. Thought and practice moves our painting style, but it’s incremental, just like the Mary Day docking. Rush that by copying someone else, and you risk being a parody.

I don’t know a single serious artist who thinks he or she is painting well—even the ones who are highly successful. We’re all on a quest; our vision is constantly changing. But through all that, we have something that’s immutable. For lack of a better term, I’ll call it our styles.

My students make me proud

Lemme show you some pictures…

Linda DeLorey, from a class assignment on painting snow.

I’m turning into one of those old ladies who carries photos around in her phone and shows them to total strangers. However, they’re not pictures of my kids or grandkids (or even the dog). Instead, they’re my students’ paintings. I’m very proud of them.

Amy Thomsen, from a class assignment on painting trees.

People are embracing distance learning, even in the evening after a long day of work. I don’t know if that’s because of the continuing reach of COVID, because it’s winter, or because the limits of geography are lifted.

David Broerman, from a class assignment on painting snow.

It’s turning out to be as much a group of friends as my summer plein air classes. On Monday night, talk turned to baking, a long digression that ended with Mark going to his refrigerator for his sourdough starter. My Tuesday class includes sisters who live across the country from each other. It’s all far warmer and personal than I ever imagined.

Mark Gale, from a class assignment on color substitution.

Lorraine Nichols, from a class assignment on color substitution.

I’ve written extensively about learning how to teach with Zoom. If there’s been a gift from 2020, it’s getting me over the hurdle of video. I used to loathe being on camera; now I don’t even notice it. There’s been lots of trial and error and I’ve upgraded my cameras and monitor. That was worthwhile. With the proper equipment the video barrier seems to evaporate.

Lori Capron Galan, from a class assignment on reflections.

I have Mary Byrom to thank; she's the one who coached and cajoled me past my resistance. That's why I pay the favor forward to other teachers when I can.

Carol Durkee, from a class assignment on color substitution.

Beth Carr, from a class assignment on color substitution.

Zoom has made me a better teacher. Instead of teaching reactively, I’ve been forced to be far more proactive in designing lessons. Teaching without geographical boundaries means I’m getting serious students. They’re working extremely hard, and every one of them is improving.

Sharyn Brusie, from a class assignment on reflections.

That's resulted in a long syllabus that will be the basis of a book, should I ever sit long enough to get some writing done (my New Year resolution.) 

Janice Vierke, from a class assignment on reflections.

We have a Facebook group where my students share recent paintings. I've nabbed some for you; I think they speak for themselves. There isn’t enough room in this blog to feature all of them, so I’ll catch up with the rest of them later. In return, I promise to not corner you at the grocery store and show you pictures of my grandkids, cute as they are.

Carrie O'Brien, from a class assignment on reflections.

Patty Mabie, from a class assignment.

Kathy Mannix has sold two paintings since starting my classes earlier this year. Amazing.

Mary Silver lives in the Texas hill country, where snow is generally just a happy dream.

Monday Morning Art School: different strokes

The best way to learn about your brushes is to experiment. Your brushwork contributes immeasurably to the quality of your painting. Don't dab or be diffident; plan your strategy and then execute it with boldness.

A spalter or mottler is a most useful watercolor brush.

On Friday, I gave you a guide to buying brushes. What are you going to do with these brushes now?

OIL and ACRYLIC

In the following illustrations, I've tried to keep the amount of solvent the same (except with the fan brush).

Above is a sable flat brush by Rosemary & Company. It can put down a very smooth surface and offers a lot of control, but it doesn't carry the quantity of paint that an equivalent bristle brush will. I save sable for glazing or blending.

This is a hog bristle flat brush. The paint it lays down is both rougher and more impasto than the sable.

Flat brushes make an immediate, energetic mark. They're excellent for fast, powerful surface work, long sweeping strokes, and blocking in shapes.

Used on their sides, they also make great lines, far more evenly than a small round can do.

Two rounds of very different sizes. A round is a more lyrical brush than a flat, and is a classic tool for painterly surface marks. It can be used to make lines that vary from thin to thick. A pointed round is used for fine detail. Bristle rounds tend to lose their points very quickly, however.

The great advantage of a filbert is the variety of brushstrokes you can get from one brush. This is great for single strokes that taper, such as in water reflections. Its rounded edges are good for blending. Set on its side, it makes nearly as good a line as a flat.

A bright is a less-flexible version of a flat. It's great for short, powerful strokes or situations where you want a lot of control.

A fan brush probably has no place in a plein air kit, but I carry one anyway. I use it for blending, as on the left, although some people like using it to make whacked out marks as on the right. The problem is, it can carry very little paint, so its marks tend to be either gooey, as above, or very abrupt.

In my studio, I just use a clapped out soft-haired brush to blend.

Many plein air painters also carry liners and riggers, which are useful in paintings that are built up smoothly. I don’t paint that way, so I seldom use them. Another brush that is good for detailed work is an angled brush. I don't have one of them, either. You can do almost any work you can envision with just the brushes I've shown you above.

WATERCOLOR

Watercolor brushes are softer than oil-painting brushes. The most expensive are natural bristles, and the difference is usually worth paying for. Natural bristles combine strength with suppleness and hold more paint than synthetics. Unlike oil-painting brushes, your watercolor brushes should last a lifetime, so buy the best you can afford.

In general, watercolor brushes drop more pigment the more vertically they're held. You can use this to move from a filled area to a broken one in one brush stroke. In all the following examples except for the mop, I've held the brush both ways. A good general rule is to carry the vertical brush slowly and in a controlled manner; pull a horizontal brush more rapidly to get the least amount of paint contact with the paper.

Made with the spalter brush at the very top of the page.

The brush I used for the photo montage at the top of the page is a 2" flat synthetic mottler or spalter brush. I like this shape for both oils and watercolor. It's a relatively inexpensive brush that gives a beautiful wash. It's useful for covering large areas quickly, but with precise edges.

A flat gives you good even washes. Used on its side, it can give you a controlled line.

A bright is a shorter version of a flat. More punch with less pigment.

Flats and brights give you nice flat washes, but can be used to make expressive lines as well. Brights have more control and carry less paint, just as they do in oil painting. Turn them on their sides to make a controlled line. Twisting the brush while painting gives an infinite variety of shapes. So too does varying the ratio of paint and water.

You can't do either of these things in any other medium.

Because of the way watercolor bleeds, its brushes can be used in ways not possible in any other medium--a long blend of different pigments, or by painting a shape in clear water and then dropping pigment into it.

Round brushes give more lyrical lines than flats do.

I don't normally carry riggers with me in either watercolor or oils. (They're meant to paint perfect lines, and my world-view apparently doesn't have many perfect lines in it.) Most of my line work is done with rounds. They do not give as much control on long lines, but they are very expressive.

A mop brush gives a perfect wash, but it does so much more as well.

Squirrel mops are the most uniform wash brush you can use. It's virtually impossible to make them skip, so use them where a lovely flat wash is a goal. But a good mop can also point, hold vast amounts of paint and sweep across the paper in style.

I think Guillo the dog ate my sea sponge.

Natural sea sponges are multi-purpose painting brushes. Use them to apply or remove paint. They can be as subtle or bold as you wish.

The brushes you really need

You don’t need to spend a fortune to paint.

Channel Marker, 9X12, oil on canvas, available.

OILS and ACRYLICS

Expensive brushes are not the place to throw money for the beginning oil or acrylic painter—good quality paints are far more important. Still, brushes do change how the paint sits, and you need proper tools.

For alla prima painting in oils, you want long-handled hog-bristle brushes. They are less expensive than softer hairs like sable. I like Princeton 9700 series and Robert Simmons Signet hog bristle brushes.

Princeton also makes synthetic brushes that are good value for money—the 6300 series. Anything softer really isn’t appropriate for alla prima painting in oils. Acrylic paints will tolerate a little more flexibility, but avoid anything labeled for both watercolor and acrylic—they’re too soft. Princeton has a good chart of fiber stiffness, here.

Home Port, oil on canvas, available.

An assortment of rounds and filberts, a few large flats and an optional fan brush should suffice. More than a handful is overkill. Most workhorse alla prima painting happens between sizes #6 and #12, with a few smaller brushes for detail work, and larger brushes for bigger canvases.

If you like painting itsy-bitsy lines, invest in a rigger and a #1 round. I get more mileage out of spalter brushes, which are large, inexpensive flats for covering lots of area fast. I also keep a few soft sable brushes for glazing and blending.

Parrsboro Sunrise, 11X14, oil on canvasboard, available.

Bristle brushes tend to form a flag (a v-shaped split) at the end over time. If the brush is made properly, with good interlocking bristles, it will have a natural resistance to fraying. However, oil and acrylic brushes can’t tolerate letting paint dry into them, or being left standing on their bristles in solvent. You can wash brushes with Murphy’s Oil Soap, saddle soap (nice), specialty brush soaps, Fels Naptha, or even shampoo or detergent in a crunch. The important thing is that you do it promptly, before your paint has a chance to set up.

First, remove the solids by swishing them around in solvent. Then, put soap on a rag and work it into the bristles from the ferrule down to the bristles’ end. Be sure you’re washing the inside bristles, not just the surface. Repeat until the suds run clean. Shake excess water out, shape the brush slightly with your hand, and let it air dry.

Sometimes it rains, oil on canvasboard, available.

WATERCOLOR

Brushes are far more important in watercolor. I like Rosemary & Co. but they are very expensive. I recommend Princeton Neptune brushes for new painters. A ½” flat, a 1” wash brush, a #6 quill and a #8 round will get you started. If you’re going to invest in a mop, squirrel is better than synthetic. A set of short synthetic flats (or mottlers, as they’re sometimes called) in ¾”, 1” and 1½” will round out your collection.

Riggers and liners are tiny brushes for making very fine lines. They’re more useful in watercolor than they are in oils, in my experience. I buy the cheapest ones I can find because I’m always wrecking their points.

Lastly, you should have a scrubber to take out mistakes. You can buy them purpose-built, or you can just use an old hog-bristle brush.

Never leave your brushes standing in water, even as you work. Cleaning watercolor brushes is far easier than cleaning oil brushes. Hold them under the tap and let the pigment wash off with the flow of the water. I have never washed my brushes with soap, but if you find your synthetic brushes have stained, you can use a small amount of bar soap on them. Squeeze the water out and reshape the heads. That’s all there is to it.

Monday Morning Art School: scaling up a painting

It may seem time-consuming, but with big paintings it saves a lot of work in the long run.

My watercolor sketch. It's gridded on a piece of plexiglass laid over the drawing.

On Friday I wrote about losing my painting reference and going to great lengths to find substitutes. The human mind being so fickle, writing that post made me suddenly realize what and where my original reference was. I came downstairs to my studio convinced that I would wipe out the interloping boats and go back to my original drawing.

I drew the mast positions in with charcoal and a straight-edge before starting to paint. That way their angle will match my sketch.

However, when I looked at the canvas again, I realized it wasn’t that bad. Different from my original intent, certainly, but not bad. I walked the dog and pondered. By the time I was home again, I’d determined that I should just paint both iterations. It was possible to differentiate them enough to make two different works out of them, both speaking to the flying sensation of sailing.

That meant gridding up a second version. This time I decided to go with the original aspect ratio of the sketch, rather than cropping it. I liked the yawl I’d truncated the first time around.

Straight lines, curves--it doesn't matter. Just find the point at which they intersect the grid, mark those points, and work from there. I usually do this in monochrome but since I was working from a watercolor sketch, I just massed color.

I have a projector, but I find that gridding is more accurate and takes less time. Knowing how to do it is imperative for large projects, but it can be surprisingly useful in small paintings, too. Whenever you have trouble going from your thumbnail to the canvas, gridding is your go-to answer.

Boats v.2, laid out 24X36 in just a few hours. Later today I can actually paint them.

I realize many artists are math-phobic, but there are times when a bit of arithmetic can save you a world of pain.

First, work out whether the aspect ratio of your sketch is the same as the canvas. This is the proportional relationship between height and width. Sometimes this is very obvious, such as a 9X12 sketch being the same aspect ratio as an 18X24 canvas. But sometimes, you're starting with a peculiar little sketch drawn on the back of an envelope. You can use a trick you learned back in elementary school.

Remember learning that 1/2 was the same as 2/4? We want to force our sketch into a similar equivalent ratio with our canvas.

Let’s assume that you’ve cropped your sketch to be 8” across. You want to know how tall your crop should be to match your canvas.

Write out the ratios of height to width as above.

To make them equivalent, you cross-multiply the two fixed numbers, and divide by the other fixed number, as below:

Use your common sense here. If it doesn't look like they should be equal, you probably made a mistake. And you can work from a known height as easily as from a known width; it doesn't matter if the variable is on the top or the bottom, the principle is the same.

The next step is to grid both the canvas and sketch equally. In my painting above, my grid was an inch square on the sketch and 4" square on the canvas, but as long as you end up with the same number of squares on both, the actual measurements don't matter. You can just keep dividing the squares until you get a grid that's small enough to be useful. For a small painting, that could be as simple as quartering the sketch and the canvas. I use a T-square and charcoal, and I’m not crazy about the lines being perfect; I adjust constantly as I go.

The last step is to transfer the little drawing, square by square to the larger canvas. I generally do this in a dark neutral of burnt sienna and ultramarine. On Friday, however, since I’d already done a grisaille and a watercolor sketch of the subject, I just transferred large blocks of color. It may seem time-consuming, but with big paintings it saves a lot of work in the long run.