Join John Derry for an in-depth discussion in this video Using the Wet, Load, Mix, and Flow controls to adjust color behavior, part of Photoshop CS5: Painting with the Mixer Brush.
Once you have an understanding of the color wells under your belt, you can start to use these various controls to modify how your strokes look. The Wet, Load, Mix, and Flow controls are all various aspect of the color wells, and we're going to take a look at them now. I'm going to begin by talking about the Load control, and to start, I also want to turn these all the way down, just so we begin with basically a blank slate. And the Load control controls how much color is in the color well. You cannot take this down below 1%.
Unlike the Wet control, the Load control can only go down to 1%. This ensures that there's always some color in the color well of the brush. So I'm taking it down to its minimum setting, and when I paint with a color, you'll see what happens is the stroke runs out of paint very quickly. That's because there's very little paint in the well. I refer to this as a stroke life. So you can control the life of the stroke, based on the setting of the Load control.
If I turned it up just a bit, we'll see now we get a stroke that's a bit longer, but it will eventually run out of color. So the higher this value, the longer the life of the stroke. If we turn it up to 100%, we're going to get essentially what the earlier models of brushes in Photoshop have done, and that is an infinite color well. So at 100%, I can just sit here and paint, and it will always, continuously deliver color to the brush.
So now we understand how we can control the color well; let's look at how we can control the pickup well in relation to what's happening with the Load control. I'm going to switch to a separate image here, and you'll find this image in your Exercise folder. It's called color bars. And let's just start with the current setting here. At a Wet value of 0, I basically get a opaque stroke. Now, I'm going to turn this up a bit, and you'll see what happens is the underlying color is contributing to the makeup of the stroke.
I started on white, so some white was picked up by the brush, mixed with the purple we're using, and as I went over these colors, each of these colors was contributed to the stroke to make up this bit of smeary purple that we're seeing. Now, I'm going to go ahead and turn this all the way up to 100%, because I want to show you that at 100%, you really don't see much difference from a 1% setting to 100% setting. I can see some subtlety and smoothness in the transition of colors at 100%, over what I see at 1%, but it's not dramatically different.
And I want you to be aware of that. While there's this whole range of 100% here, the way the Wet control is currently set up, you don't get a remarkable change based on all of these values that are contained from 1 to 100%. I still tend to adjust it, but it really doesn't seem to have a whole lot of difference. Now let's talk about the Mix control. We're playing with both Load, which is the color well, as well as the Wet slider, which is the pickup well. The Mix slider controls the ratio of these two values together.
So if I turn Mix all the way up to 100%, it's going to set it so that 100% of the pickup well or the Wet value becomes the contributing factor to the brush. So there is no color from the color well being mixed in to this value. It's all 100% Wet value. If I turn this down aways, we'll see that now some of the purple is contributing to the color, but it's in a ratio that's consistent with what this value is in the Mix.
So Mix is just playing with the ratio of these two colors' contribution to the total stroke. Finally, we have the Flow control, and the Flow control controls the overall settings. It's like a master control. If I turned Flow down to a low value here, you'll see that I get some color, but it's very slowly being added to the canvas. And if I turn it all the way up, I'm going to get a much greater application of color within my stroke.
You'll notice there really is no opacity control associated with the Mixer brush. The Flow control basically acts as a replacement for opacity. So if you want to subtly build up your strokes, a low value is going to give you that capability. On the other hand, if you want to start building up color quickly, use a high level of Flow in order to start to pick up and take all of the other factors of your brush into the stroke, to build up color at whatever rate the Flow rate is set to.
You probably will spend most of your time making adjustments to these brushes in order to customize the look of your strokes. Small changes can make differences, but also be aware that with something like the Wet control, large differences really hardly make any change at all in your stroke. So my best advice is to spend time playing around with these controls, and once you get the understanding of these four controls, it will go a long ways towards enabling you to create very specific strokes that you want to work with.
- Understanding the axes of motion with a Wacom tablet
- Choosing a brush shape and Bristle Tip
- Adjusting brush angle
- Loading color and control the behavior of the Mixer Brush
- Modifying surface texture
- Simulating the texture of canvas
- Saving tool presets for brushes
- Creating a painting from a photograph
- Painting from scratch with the Mixer Brush
Skill Level Intermediate
Q: What factors affect how well the mixer brushes in Photoshop perform? Does document size (i.e. 72dpi vs. 240dpi) affect the performance of the brushes? How can I maximize brush performance?
A: The recordings for this tutorial were generally done at a standard screen resolution, but a real-world situation will often require higher resolutions. For example, offset printing generally dictates files at 300ppi (pixels per inch). Inkjet printing is often discussed in terms of 240ppi. For web-based viewing, imagery at 72ppi is considered acceptable. You can easily determine the pixel resolution of an image by multiplying the size in inches by the above ppi (pixels per inch) factors.
Let's use a typical real-world size as an example: 20" X 24". This is a common photographic print and frame size.
72ppi = 1440p X 1728p = 2,488,320 pixels
150ppi = 3000p X 3600p = 10,800,000 pixels
300ppi = 6000p X 7200p = 43,200,000 pixels
Note that each of these resolution factors quadruples the total pixel count.
It is the amount of pixels being manipulated that dictates both application and brush performance. With this in mind, we can state that performance decreases as image pixel size increases. There are three primary factors that affect an application's ability to handle large pixel-based manipulation.
For the full FAQ, please download the PDF file here.