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September 6th, 2005 #1
Creating a Smeary Oil-style Brush in Corel Painter
Creating a Smeary Oil-style Brush in Corel Painter
In our previous installment (Creating a Static Bristle Brush), we created a bristle brush by using the Static Bristle Dab Type. The resulting variant has a lot of character, exhibiting variable-sized bristling within the brush's strokes. The applied color, however, is flat and opaque much like tempera paint. In this installment, we are going to add wet and smeary qualities to the brush. This will allow the brush to pick up and mix with any underlying color. The result is a brush with the characteristics of oil paint. Let's go!
Well, well, well...the Color Well
Painter's brushes utilize a color well to apply color, as well as blend with any existing color underneath an applied stroke. These two attributes are controlled by the Resaturation (apply color) and Bleed (pickup underlying color) sliders found in the Brush Controls: Well palette. In fact, these two attributes are so crucial to modifying Painter's brushes that the Resaturation and Bleed sliders are additionally located on the Brush Property Bar. Note that these controls will not be present for non-color-bearing variants. By having these important controls instantly available, you can quickly make subtle adjustments to the color behavior of the current variant.
If Resaturation is greater than 0%, the current color will be applied to the canvas (or layer). If Bleed is greater than 0%, any underlying color will be blended into the stroke. In most brush variants, both the Resat and Bleed sliders are set greater than 0%. It is important to understand that the interrelationship of these two settings can be subtle or dramatic. For example, when Resat is set to 0% and Bleed is greater than 0%, the brush will act as a blender, mixing underlying colors together. The actual percentage setting of Bleed is used to adjust how much or little the underlying colors are inter-blended.
As a general rule, when Resat is set higher than Bleed, the current color will dominate and the brush will primarily lay down color. Note that The current Bleed setting will affect how much undercolor pickup is a part of the brush's behavior. Conversely, when Bleed is set higher than Resat, the underlying colors will dominate the color of the brush stroke, and the current color will not aggressively intermix with the picked-up colors (if at all). Again, the particular settings Resat and Bleed can be subtle and slight adjustments to either can alter the personality of the brush's behavior.
As I describe the various adjustments we'll be making, feel free to try out the brush on a test file. Some of the adjustments aren't even obvious unless a stroke is created with the brush.
For demonstration purposes, we will start with the basic settings of the Static Bristle brush example created in the previous tutorial, Creating a Static Bristle Brush. These settings are Resaturation: 100%; Bleed: 0%. Both of these attributes have Expression set to Pressure. Opacity Expression (General palette) is also set to Pressure.
Resaturation controls the amount of color flowing from the well. When Resaturation is set at 100%, the applied color is opaque. As the Resaturation value is reduced, less color flows from the brush. Overlapping applied strokes are recharged by the underlying color.
Bleed acts as the inverse of Resaturation; it is responsible for picking up (and adding into the brush stroke) any underlying color. Keep in mind that Bleed is disabled on a layer when Pick Up Underlying Color (Layers palette) is unchecked. As the Bleed value is increased, more of the underlying colors is added into the stroke color.
Cool Tip: If Resaturation is set to 0% and Bleed is aggressively turned up, then a brush will act as a blending brush.
The Zen of the Smeary Variants
Armed with an understanding of Resaturation and Bleed, you now have a great deal of power over the behavior of Painter's brushes. And, because the sliders for these important attributes are located in the Brush Property Bar, you can quickly make on-the-fly adjustments without digging down into the Brush Controls palette.
I'll reiterate how Resaturation and Bleed are currently set up to work in our example. If Resaturation is greater than Bleed, then the current color dominates and is applied. Conversely, if Bleed is greater than Resaturation, then the underlying color is picked up and mixed into the current color. We are using Pressure to control both of these attributes. By using Pressure, the visible effects of Resaturation and Bleed increase with greater applied pressure. Now, here is where things get a bit unintuitive.
In order to have a brush that both applies and smears color, we need to alter the pressure behavior of Bleed. Instead of having pressure increase the Bleed attribute, we want pressure to decrease Bleed. Why? If Bleed is at its maximum when minimal pressure is applied, it will cause the brush to act almost exclusively as a blending brush. As pressure is increased, Resaturation takes over and the brush transitions into a color-wielding tool. How can we get Bleed to behave in a reverse fashion? We utilize the Bleed Invert checkbox located to the right of the Expression pop-up. This reverses the sense of pressure with respect to Bleed.
OK, this brush is beginning to get interesting with one glaring restriction: the color well is currently able to only pick up a single color when smearing. A physical paint brush typically picks up multiple colors across its width. The behavior of the Artists' Oils is a good example of this. How can we get our Static Bristle example to behave in a similar manner? By enabling Brush Loading, of course! This is done by checking the Brush Loading checkbox located at the bottom of the Well palette. When Brush Loading is enabled, the Well picks up multiple colors. In the topsy-turvy world of inverted Bleed, higher values do not translate into greater pulled color. There is no "correct" setting; it is totally season-to-taste. As a starting point for use with Brush Loading enabled, I recommend a starting value of around 20%. If you want the brush to apply color, as well, remember to turn Resaturation a bit (I recommend 10% as a starting point).
Time to Play!
If you've been following along for the past couple of weeks, then you have gained a great deal of control over your brushes. This installment provides you with a shiny new smeary oil-like brush to play with. I suggest that you take it out for a spin and make a few adjustments to suit your personal style. Post some examples of your newest brush! For my next installment, I'll show you how to add a sense of three-dimensional depth and gloss to this brush's strokes. Now go play!
Viva la Painter!
Pixels—It's all in how you arrange them!