Oil Paint is pretty much the Rolls Royce of paints, worldwide it is the most respected and sought after of paints for all of its beautiful attributes and qualities. A lot of people, even longtime artists shy away from it because of the technical aspects, the drying times, the brands of paint with their different binders and pigments, chemicals, mediums, costs, and so on. Honestly, coming from someone who has been oil painting since high school, it is really not that big of deal. Oil Paint is a lot easier to use and work with than manuals, blogs, and many artists seem to think it is. It isn't the scary, confusing, chemical ridden, drying time insanity people say it is, unless you make it that way. Like anything else, it will only become a confusing mess if you allow it to become one.
A little crash course in oils: * They are pigments bound in a drying oil (usually linseed) * Oil paints dry by oxidation (chemically through oxygen) they don't dry like water, naturally. * Oils can only be thinned and cleaned with solvents, turpentines, turpenoids, or oil mediums. * With oil painting there is one main traditional "rule" that's followed, and it is called "FAT OVER LEAN."
And this is probably the biggest fear, hesitation, and pain in the ass people have with oil painting. People hear "fat over lean" and pull their hair out. I'll explain it:
Fat Over Lean boils down to this: When painting in layers use thinner, less oily layers to start out, and progress with more oil each layer until your top layer is the most oily. This is to ensure that every layer has time to dry and no layer stays wetter longer, or dryer longer than it should. If a layer of thin oil paint is put on top of a layer of fat, oily paint, that top layer of thin paint can crack, crumb, and flake off, because the foundation on which it stands is mushy and wet. But if you put a fat oily layer of paint on top of a thin, dryer layer of paint, it will hold just fine. Make sense?
What does "FAT" mean though? Oil paints are pigments bound in oil right? Fat means more oil, Lean means less oil. If you added some linseed oil to your oil paint straight out of the tube, you would be making it FATTER. See?
Fat Over Lean only applies to Oil Paint. Acrylics, watercolors, and everything else is exempt from this talk, it is only related to oil. A lot of people have trouble with fat over lean, they either don't understand it ( I didn't for a long time), they don't remember it while working, or they just don't want to deal with it. One of the things oil painters do to work with this principle is use mediums.
Mediums are additives that you can add to your oil paints to either speed up or slow down drying times. Mediums are usually an oil, a wax, or both. Let's say you are obsessed with the fat over lean rule and you want to adhere to it like hoyle, you will make sure that your layers are thin first, and fat second, you will add mediums to your paint in each progressive layer to add more oil (and slow down drying time) and end with a fatty oily top layer. Bottom layers dry fast, top layers dry slower, everyone's drying progressively. That's the traditional way to oil paint, it's been around for centuries and is upheld as law.
"This traditional painting method sounds like a complicated pain in the ass...can't I just paint without worrying about mediums and rules?"
The answer is actually yes to a degree. Yes you can, I do, tons of artists do, and honestly this fat-over-lean-medium business is not as complex as it sounds, in fact you can bypass most of it.
Bypass it how?
There are two instances where fat over lean basically goes out the window
1.) If you paint Alla Prima (an entire painting in one sitting) - There is only one layer of paint when you paint alla prima, if you set up an easel in front of El Capitan in Yosemite you only have a few hours to get it all in before the sun goes down and you have to leave with the whole canvas filled. That is alla prima painting. Since there are no layers drying on top of each other in this method, you have nothing to worry about. Paint wet on wet, leave it be, and move on.
2.) If you just don't use mediums. Yep. Contrary to what traditionalists teach us, you actually don't have to buy and use mediums, honestly...you can say screw it and just paint straight from the tube. You won't be struck down and killed by the angry ghosts of Jan Van Eyck and Rembrandt, you will be fine. But there are things to consider:
If you skip mediums and just paint from the tube, I suggest only one thing: Use the same brand of paint for each color. Don't mix a lukas with a charvin, or a winton with a gamblin, just use the same brand, I have found it really helps and makes things more standard. Not necessary, just a good recommendation.
By not using mediums and painting straight from the tube you are making things easier. Each layer you put down has the same amount of oil as the last, nothing is made fatter each layer because you didn't add or subtract anything. Layers won't dry at ridiculously different rates due to being wildly fatter or leaner, they will dry at a similar, healthy rate.
Now, some pigments are fatter than others by nature. Burnt Umber is leaner (and dries faster) than say Cerulean blue, so fat over lean applies in this case to a degree. Common sense tells you that blocking out an entire canvas in slow drying cerulean blue and then putting fast drying burnt umber on top can maybe, potentially crack and look screwy one day. For your first layer(s) put down umbers, siennas, and faster drying paints straight from the tube, let them dry, and then add your fatter paints straight from the tube on top. You do not need mediums or additives, just paint straight from the tube, using common sense and basic knowledge. Progress, without addition and subtraction, just work it.
When I was starting out I experimented with some mediums and oil additives, and all it did was just complicate things and honestly piss me off because worrying about medium instructions and precise "fat over lean" procedures made my head hurt. Seriously, I just wanted to paint, not be bound by stereo-manual instructions that just completely killed my artistic mood. I stopped caring about mediums and just left them behind. I took a chance and started painting straight from the tube and it was the best decision I made. I've been enjoying painting painlessly and happily since. No flaking, no cracked paintings, no fumes, no hassles, no problems. I just enjoy my labors. Isn't that the goal after all?
I follow common sense rules and my own methods. I paint in sections of a planned sketch, so I honestly don't use layering that much, fat-over-lean and these rules don't really come up that much. I'll draw out what I want to paint, I'll block in a section, get everything the way I want it, put down paint, blend, shade, blend, finish, and then move on to the next section. So in a way, I kind of paint alla prima, by painting wet-on-wet sections of my sketch on my canvas or panel. Let's say I'm painting one of my girls or beasts, maybe I'll have a bird in the background, I'll paint him until I'm happy, leave it to dry and move on. Then I'll get to her face, her eyes, her lips, etc. Nothing really overlaps and layers don't collide much, and if they do, I make sure to use my fattest colors over my thinner colors, a little basic pinch of the fat-over-lean rule. Before you know it, the painting is done, drying, and once dry there are no issues and the painting is adhered well with no problems. In a coupe months I can add a nice varnish and all is well.
I have doodle practice paintings I worked on in high school that are still completely intact as a flexible paint film and in perfect shape, that's well over a decade of drying time, and they were done with ZERO consideration of fat over lean and any principles of painting. So really, this fat over lean business and stress over technical perfection is not that scary and necessary. Honestly, you can probably throw a bunch of colors down on a canvas, kick it around, throw it in the attic for 20 years and it would likely be fine. We forget that our wood, canvases, paints, and materials are normalized and simpler now, the renaissance masters were using natural ground ingredients and equipment that were far different, they had awkward drying times and results. Thanks to research and development, our paints today are pretty standardized, they're better than they were in 1480, take advantage of that, take solace in that. A lot of the old rules are antiquated.
I do things my way, this is my method and it works for me well. If you like mediums and doing things old school then do it and enjoy it. Find your method and what works best for you, you have to find a method that makes you happy and doesn't give you headaches and stress. Worrying about mediums and strict principles just made me sick, and so did the fumes of solvents and mediums! Just another nice bonus to not using mediums, they are toxic as hell and smell up a room like crazy. If you want to oil paint but have been afraid of the medium-drying issue, honestly just skip it. Just experiment and see what works. Maybe you'll get a cracked painting, maybe you'll have no problem, just experiment on some scrappy canvases and get a picture of it all. However, I suggest you do what I did, take it easy, ditch the additives and just let the oils out of their tube freely. Use common sense and just a little bit of fat-over-lean rules when needed, but really just let it flow. It takes time to find your own method, you'll need to try different things out, but in the meantime don't feel like you are BOUND to some oil painting instruction manual written by a traditionalist. Art is about doing whatever the eff you want, however you want...not how a professor or a rembrandt scholar says to.
I love Rembrandt, but I paint my own way...you should too. Hope this helps! -Zev