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DMSS
05-12-2018, 10:40 PM
I have 3 questions about glazing.

1. I am painting a still life with an orange-brown wood table in a strong light, and with cast shadows. For the parts in the light I am using a glaze of transparent red oxide. I tried glazing ultramarine blue over the red oxide for shadows, and it is not all that dark, and it looks blue. I don't want the shadows to be blue. Should I glaze some burnt umber on top, and then adjust with subsequent layers as needed, or just continue to alternate layers of ultramarine blue and red oxide?

2. In general, should I darken colors by glazing alternating layers of complements, or should I just glaze multiple thin layers of a neutral color until it is nearly as dark as I want it and then make hue adjustments with additional layers?

3. In general, should I do multiple layers of a color that is close to the final color I am shooting for, and then adjust hue, value and chroma with additional layers, or should I be going back and forth with different colors in different layers?

Thank you for your thoughts.

Ellis Ammons
05-13-2018, 04:05 AM
i try to mix everything on the pallette as close as I can. Only glazing transparent colors when I need a chroma boost of the same color or to slightly nudge a hue. I don't try to optically mix by glazing say blue over brown to make a black, or blue and yellow to make green or something of the sort. That just complicates things. Optical mixing of the sort is more of a airbrush technique. It's doable with the hairy stick.. just needlessly difficult.

cliff.kachinske
05-13-2018, 12:25 PM
Here's something authoritative about cast shadows:

http://www.wetcanvas.com/forums/showthread.php?p=21355843&highlight=gray#post21355843

The transparent shading gray uses lamp black pigment. Presumably you could get similar effects with Golden's lamp black paint.

DMSS
05-13-2018, 02:25 PM
Thank you, Cliff. I had missed that thread. I might try that. Derek's results speak for themselves--fantastic!

cliff.kachinske
05-13-2018, 03:48 PM
Remember, you're glazing with that lamp black ...

Another approach says that a cast shadow works best if it's the complement of the object's surface. For red oxide, that would be something like cerulean blue. If you don't have cerulean, phthalo blue with a bit of phthalo green or viridian will do.

I wouldn't use cobalt blue for this because it leans a little too far purple.

To make the blue less blue, add red oxide which will pull it toward the gray and darken it. (Notice the similarity -- glazing with lamp black will darken the color and pull it toward the gray.)

Color Choices by Stephen Quiller does a great job of explaining color mixing and harmony. His color wheel is the most practical one for artists because his complementary pairs do the best job of neutralizing each other.

Personally I would go with the chromatic effect - mixing the complementary colors. To me it makes the gray more lively. But that's just me - my colors tend to sing pretty loud.

fedetony
05-14-2018, 08:20 AM
Why not premix the color you want to achieve, instead of trying to adjust it in the layering? a transparent color mix is easier to glaze until the final intensity is achieved, rather than playing both with color and intensity...
;)

DMSS
05-15-2018, 08:08 AM
Why not premix the color you want to achieve, instead of trying to adjust it in the layering? a transparent color mix is easier to glaze until the final intensity is achieved, rather than playing both with color and intensity...
;)
Some say you get richer colors by glazing one color over another instead of mixing them on the palette. For example, I've been following this recent thread: http://www.wetcanvas.com/forums/showthread.php?t=1447690 I'm trying to figure out whether I see the difference.

fedetony
05-16-2018, 09:42 AM
Some say you get richer colors by glazing one color over another instead of mixing them on the palette. For example, I've been following this recent thread: http://www.wetcanvas.com/forums/showthread.php?t=1447690 I'm trying to figure out whether I see the difference.
Interesting point, I am in the idea the color intensity depends on the amount of layers, yet if you find any visual difference by the two processes I am quite interested in hearing these results!
You may be right, by the way, because light reflects differently in different layers: If you use different colors in each layer the light will bounce changing the angles of reflection in each layer, compared to if you use a mixture, then the same angle of reflection in each layer. As consequence light is scattered differently. Is possible this brings richer colors. :)