One of the most popular techniques in oil painting is glazing. This is a multiple step process in which you will paint the entire painting first in neutral colors to get your tonal values down, then later when it’s dry, you’ll glaze over the top with transparent colored paints.
Here are the topics we’ll be discussing:
Why would I want to paint something once only to have to paint over it again?! Right? I ask myself this question all the time. But it really does have its advantages. To think scientifically about paint for a moment, imagine that each layer of transparent paint you add to your painting is like glass. The light goes through it, hitting the image under the glass (your underpainting) then reflecting back up to your eye. The more layers of transparent color you have, the deeper and richer it appears when light hits it.
I mentioned previously that there are several methods—verdaccio and grisaille being two of them. I’m going to go over a method known as imprimatura.
Glazing is a technique employed by painters since the invention of oil painting. Although in theory it is very simple, in practice glazing can be a very complex undertaking. In the simplest terms, glazing consists in applying, usually with a wide, soft-bristled brush, a transparent layer of paint over another thoroughly dried layer of opaque paint. The underpainting, as the dried layer is called, is generally monochromatic but may also contain some color. The two layers of paint are not physically but optically mixed. Glazing is similar to placing a sheet of colored acetate over a monochrome photograph. The paint used to glaze must be modified by an oil medium to achieve the correct transparency and fluidity for brushing. Glazing creates a unique “shine through,” stained glass effect that is not obtainable by direct mixture of paint.
In addition to monochromatic underpaintings, colored underpaintings can also be employed. For example, if you are painting some red drapery and want to neutralize the red, you can complete your underpainting in red’s complement, which is green. If you decide to go this route, you’ll want to experiment a bit first to see which color combinations work and which don’t. Not all paints are transparent and suitable for glazing.
Some paints are opaque and you cannot glaze with them (well, you can try). Look on the back of your paint tube to see if it says “transparent”—that means it’s good for glazing. Ideally, you want to be able to see all your hard work underneath the glaze. Some semi-transparent colors also work for glazing—it’s really a process of trial and error!
When you glaze, you’ll mix your paint with a glazing medium and again, there is no “perfect” glazing medium—different artists prefer different things. You have to experiment to see what you like! I have found that there are generally two classes of artists when it comes to glazing mediums—old schoolers and new schoolers.
Old schoolers will use old materials like Dammar Varnish, Turpentine, and Stand Oil, or Canada Balsam and Oil of Spike Lavender, or any number of other old master mediums in various ratios. Some of these are good. Some are toxic (like turpentine—yech!) and some will cause your paint to yellow and crack (like Dammar Varnish).
New schoolers will use mediums like Gamblin’s Galkyd, Galkyd Slow-Dry, Walnut Alkyd Oil, or Alkyd Glazing Medium in different combinations. These are synthetic replicas of the stuff the old schoolers are using, but they’re less toxic and scientists have come up with ways to mimic the old stuff without the cracking, yellowing, or other nasty things that come with old school mediums.
Tone Your Canvas
Earth tones like burnt sienna, burnt umber, raw umber, and raw sienna dry faster than other colors, making them ideal for this step. That being said, not all artists use browns to tone their canvas. There are a lot of different schools of thought on this that we touched on a bit in Glazing in Oil Paints when we discussed underpaintings (your toned canvas will be one of the midtones of your chosen underpainting palette). Some artists like to use neutral greys (grisaille), some use greens (verdaccio), and some others still split their compositions up and apply the toned ground and underpainting in a complement of the object being painted (for example, a still life of an orange on a green tablecloth would be underpainted and toned with blue for the orange and red for the tablecloth). It’s a pretty complicated topic with a lot of history behind it. For now, let’s just stick with brown earth tones. They are what Rembrandt used and well, you can’t argue with a master.
Begin with a blank canvas, either 11” x 14” or 18” x 24”. If you don’t have a tube of black paint, mix some by using 50% Quinacridone Red 50% Pthalo Green. Using your black paint mixture, make a mix of about 50/50 paint and solvent until it is the consistency of heavy cream. Brush it on to your canvas using a large brush then wipe it with a rag to remove brushstokes. You want a medium tone—if it’s too light, you need more paint in your solvent/paint mixture. If it’s too dark, continue rubbing the paint off the canvas with your rag.
Step 1: Squeeze out a blob of black onto your palette. On the other side, squeeze out a blob of titanium white paint.
Step 2: In the middle of your black and white blobs, mix exactly 50% white and 50% black. This will give you your 50% neutral grey. Now between your 50% neutral grey and your pure black, mix three more colors that will be your darkest values. On the other side of your 50% neutral grey, mix another three values with more white that will be your lightest values. It helps to print out a value scale to keep next to your palette so you can compare the values you’re making with it to keep you on track. Right click on the image below and save it to have a printable value scale for handy reference.
Some people like to have even more values than this, but I think 9 is a good number so that 1) you don’t get too confused with 20 different values on your palette to choose from, and 2) it divides up nicely into 3 darks, 3 midtones, and 3 lights.
Step 3: With this technique, it’s easier to work from a photograph than a still life since you can make a photograph black and white but an apple…not so much. Take your reference photo and print one in color and one in black and white (or photocopy—whatever suits your fancy). This doesn’t need to be on photo paper—it fact, it helps if it’s just on plain paper since it reduces the glare you get off shiny photo paper. Keep the color photo handy for later on when you start glazing with your colors—you’ll want to match them to your photograph as you’re mixing.
Using the black and white photograph, start painting in the darkest areas first, then move to your midtones and at the very end you can add your highlights. Don’t use your pure titanium white unless it’s for the absolute brightest highlight, otherwise you won’t have enough contrast to make it seem really reflective.
Make sure to paint in your background as you work on the main subject because remember from our color theory lessons that color is affected by its surroundings. See how the values change even when I remove the warm brown of the palette in the picture above:
Even though we’re not working with color yet, values are also affected by their surroundings, so if you wait too long to add in your dark background, you may be surprised to find that you’ve painted your main subject too dark when it was still on a light colored surface.
Step 4: When you’ve finished painting the entire painting in black and white, wait. Start another painting, work on a drawing, do some gardening. When it’s completely dry (2-5 days) you can start to glaze on top with your transparent colors.
At this point, you’ll need to add to your paint stash. Which colors you add will depend on the subject of your painting, but you’ll want the colors to be transparent or semi-transparent.
How do I know if it’s transparent?
The tube of paint will either say “transparent,” “semi-transparent,” or “opaque” on it or it will have a symbol. Some brands (Sennelier in particular) may have a square on the back of the tube that indicates the transparency of the color. This is from Sennelier’s website and shows the three squares (circled in red):
Ultramarine violet is semi-transparent, while Dioxazine violet is transparent and King’s Blue is opaque. This is a little confusing though because this guide is printed on white paper and Sennelier’s paint labels are black, so on the tube of paint, a black square indicates full transparency while the white square means it’s opaque. This is confusing, I know. If you’re not sure, ask someone in the art store for help. It’s what they’re there for and generally are more than happy to talk about paints with you (they work in an art store for a reason!).
Here’s a list from Gamblin of suitable transparent colors for glazing:
Dioxazine Purple — cold purple that can be used for a black
Indian Yellow — warm yellow makes painting look lit by sunlight
Manganese Blue Hue — cool (toward green) transparent blue
Perylene Red — cool red with dramatic yellow undertone
Phthalo Blue — 20th century replacement for Prussian Blue
Phthalo Emerald — warmer, more natural looking Phthalo Green
Phthalo Green — cold, dark green with great transparency and tinting strength
Quinacridone Red — cool red replacement for Alizarin and makes high key tints
Quinacridone Magenta — cooler high key red
Quinacridone Violet — clean, warm violet
Transparent Orange — warm orange for sunrise/sunset
In addition to those transparent paints, these colors provide the abstract painter with a unique set of visual possibilities:
Black Spinel — only black with neutral masstone and tint, dries matte
Hansa Yellow Deep — golden yellow, semi-transparent
Mono Orange — clean, bright semi-transparent color, masstone of Cadmium Orange
Mars Black — dense, strong mark making black
While it’s best to use transparent colors for your glaze, the truth is, you can glaze with semi-transparent and even opaque paints if you add enough glazing medium.
If you’re painting a portrait, you’ll want to get a cadmium red medium and yellow ochre. These will act as your skin tones when you’re glazing. See the article in the Student Resource Center, Vermeer’s Artistic Technique.
The most common and traditional glazing medium is a mixture of Dammar varnish, turpentine, and stand oil. There can be problems with this mixture, though, because Dammar varnish has a tendency to yellow over time and turpentine is toxic and very smelly. There are a lot of other alternatives to this mixture, and Gamblin makes some very good, modern mediums that are designed not to yellow and are much safer to use. Galkyd and Galkyd Slow Dry are good alternatives, as is Utrecht’s Alkyd Glazing Medium (which is what I use, mixed with a little Walnut Alkyd Oil).
When beginning your glaze, remember your fat-over-lean rule (more oil = more fat, less oil/more solvent = more lean). The nice thing about alkyds is that they’re pretty neutral in the fat/lean scale. Alkyd mediums are far less toxic than traditional oil mediums. They dry glossy and transparent. To extend the “open” time (or how long it stays wet/flexible) of fast drying alkyd mediums, small amounts of oil can be added. To prevent wrinkling, no more than 10% is recommended by Gamblin. Alkyds dry within 24 hours, so it works very well for those who work with transparencies and glazes because layers can be applied overnight.
How to use your medium:
When you begin glazing, read the label of the glazing medium you’ve purchased. It should tell you how much you should add to your paint. Some mediums, like Walnut Alkyd Oil, will “bead” up if too much is added to the paint, so you’ll need to use less than if you were using just a straight alkyd medium.
On your palette, lay out some of your transparent colors as well as a little container of your glazing medium. Pick up a little of one color and in the center of your palette, mix it with a little glazing medium. If it’s not transparent enough, add more medium until it gets to the desired thinness. It’s transparent enough if you can still see your underpainting—the goal is to be able to see your grisaille painting underneath the applied color.
I don’t expect you to follow along with any of these videos—they are just to give you an idea of how this artist is using the glazing technique. Watch all four videos in their entirety to see how this technique is done (all four videos total about 46 minutes).
An Intro To Glazing In Oils With Cynda Valle
Our Beginner’s School instructor, Cynda Valle, has put together a brief (13 minute) video explaining some of the basics of glazing in oil paints. Watch this video for some insight as to how and why to glaze with oils:
Glazing Time Lapse with J. Schisler
JSchisleroilpainting has a set of three videos that are a time-lapse of him painting a still life of three oranges (tangelos?) starting from the sketch and underpainting all the way to glazing and finishing touches.
Video One shows you the sketch and underpainting process. He’s covered his Masonite panel with a little Maroger’s Flemish Medium (a combination of Black Oil and Mastic Varnish). Black oil was made by boiling lead with linseed oil, making it toxic. Gamblin, of course, makes a modern version of this without all the nasty chemicals called Neo Megilp, which thins down oil paints but still gives them body.
He is laying down some linseed oil first to help the paint flow and blend better so he don’t end up with hard lines (because there is no such thing as a hard line in nature…don’t paint hard lines!). Schisler is also painting wet-into-wet, so the fact that he’s using straight paint after laying down some paint that’s been thinned with medium is okay because all the paint layers are still wet.
The first layer of paint is all neturals. He’s using a burnt umber. He could also have used raw umber, raw sienna, burnt sienna, or a neutral black (like the one you’ve made already).
A note: After 1:16, he stops talking and plays the same song several times in a row. If you’re like me at all, you’ll want to mute it after 1:16. At 8:32 he starts talking again. Un-mute.
At about 4:35, you’ll notice a wooden dowel that he’s resting his hand on. This is called a mahlstick (or maulstick). It’s essentially a thin wooden stick with a padded end that can be laid on the easel so the artist can steady his or her hand without laying it directly on the canvas. It’s particularly helpful when you have a lot of wet paint on your canvas.
Sometimes he turns his canvas around. This is totally okay to do and in fact helps a lot! In determining a composition, it helps to turn your canvas upside down to see how your arrangement works or doesn’t work and when you’re painting, some areas are easier to get to when the work is turned another direction.
Video Two begins the glazing process. My guess is that he has pre-mixed his colors to match his still life before he starts painting. This helps just so you don’t have to stop in the middle of your painting to make the right color. When you start painting, do your best to mix the color in the midtone of your object. That color’s compliment (if it’s orange, then blue; if it’s red then green, etc.) will become the shadow area and adding a little white will make the lighter midtones and highlights.
The very first thing he does is lay in his background. Doing this will help you better assess the actual coloring of your objects. You’ll notice how he starts with the shadows first and even though they’re oranges (orange, right?), he’s painting the shadows in a cool purplish-blue color! This is because blue is across the color wheel from orange, so it will neutralize his subsequent orange glaze on top, making it a cool, receding color, giving the illusion of depth and mass. He adds his lighter orange colors after his shadows and midtones so the paint doesn’t muddy.
Again, if you don’t want to listen to his music, you can mute until 9:50 when he starts talking again.
Video Three continues refining the still life. When he adds in the highlights on his oranges, notice that they’re not white. White is what we expect the highlight to be, but if you take a piece of cardboard and cut a small, ¼” hole into the center of it then look at your object’s highlight, I’ll bet it’s not actually white. Put a piece of blank, white printer paper next to that hole and look again. Is it the same color? If so, then you’ve got a white highlight! But unless you’re painting something really reflective (ceramic, chrome) your highlight is probably colored. The highlight on these oranges is really a bright orange/yellow.
Experiment on a small canvas with your new medium, the new paint, and some of the paints you already own. How does the consistency of the paint change when you add just a little bit of medium versus a lot of medium? How does the transparent paint look next to your other opaque and semi-transparent paints? Make notes on the canvas as you go along so you’ll remember for next time.
Paint a simple still life in grisaille. Choose something simple like a pear or a lemon and set it up with a single light source hitting it from one side, making a shadow on the other side. Once your grisaille painting is finished and dry, start experimenting with your colors and glazing on top of your black and white painting. This process may take several days or even weeks! Don’t feel like you need to do it all in one day—it just won’t happen. Keep in mind that when you’re adding your color, you’re still painting, not just coloring. For example, if you’re painting a green pear, you may glaze it mostly with green paint, but it the shadows add a little bit of blue or a touch of yellow in the highlights. Heck, there may even be some red in there. Look closely when determining your colors.
I always like to think of the Fauvists when I’m painting. French for “The Wild Beasts,” these guys were innovators in color during the early 20th century. Henri Matisse was one of the major players and his Portrait of Madame Matisse is a benchmark for this artistic movement:
Although this painting was done using the Alla Prima method, I want you to see the colors Matisse is using. Matisse exaggerated all his colors, as you can see above with the green stripe running down the length of his wife’s face. Gauguin was also a part of the movement and once said to his friend Paul Sérusier, “How do you see these trees? They are yellow. So, put in yellow; this shadow, rather blue, paint it with pure ultramarine; these red leaves? Put in vermillion.” The point was that they weren’t toning down colors, but plumping them up and exaggerating them. You don’t have to be this wild with your colors, but look for subtle colors in your still life. That shadow isn’t grey or black…it probably has some blue, purple, or even orange in it. Is there a reflected light in the shadow right where it meets up with the object? What color is that? It’s probably in the same color family as your object (maybe a light green for your pear?). The most important thing about painting is seeing. Don’t paint what you think you should see—paint what you actually see!
Now go paint! And share photos of your work with us using our submission form.