More Photoshop CS5 Mixer Brush Tips

(This is the second of two articles on the Mixer Brush that I've written.
The first can be found here.)

A while back I wrote an article about some of the technical shortcomings of Photoshop CS5's new Mixer Brush, and how I've managed to overcome them for the time being (link). In this article, I discuss some new practical tips for using the Mixer Brush, including how to create a mixer palette, loading multiple colors quickly by using a custom brush, simulating real-world brush sizes, and improving details and color.

1.) Create a Mixer Palette

If you use Corel Painter, you probably have noticed the inclusion of a mixer palette, which allows you to mix colors in a real-world manner before applying them to your painting. With the inclusion of a new Mixer Brush in Photoshop CS5, not including a mixer palette in CS5 seems like a huge oversight. Creating one, however, is actually a simple matter.

With Photoshop's tabbed document layout, floating windows stay visible in front of all tabbed documents (Windows PCs only). In other words, to simulate a mixer palette in Photoshop, you simply need to create a new document and then 'tear' the document tab out of the default tabbed layout, so that the new document floats in its own window.

Your new 'mixer palette' will remain on top of your painting so long as your painting remains tabbed. Just resize the window to your liking, then add and mix your colors. While working on your painting, you won't need to switch documents to sample colors from your palette either - just hold the 'Alt' key and click in your 'mixer palette' to sample colors.

2.) Make a Custom Brush to Easily Load Multiple Colors

Loading multiple colors with the new Mixer Brush in CS5 often yields more realistic results, especially when laying down large fields of color. Getting the desired colors onto your brush, however, requires a little preparation, as you need to mix the colors first and then sample the image. Using a custom brush with randomized 'Color Dynamics' settings can save a lot of time by producing a multi-colored swatch from just a single color.

To create a special 'Color Palette Brush' to mix colors for you, select the default round brush preset with the regular Brush Tool, and then adjust the 'Brush Tip Shape', 'Scattering' and 'Color Dynamics' settings to something like the following:

Now you can simply pick a desired color and then use the custom brush to quickly lay down a multi-colored 'swatch', which you can then sample with the Mixer Brush. Just make sure 'Load Solid Colors Only' is turned off in the Mixer Brush Tool Options (shown in the first picture). (Note that the sample size or 'swatch' you lay down must be as large as the Mixer Brush's size in order to fully load the brush.)

To create multi-colored gradations for sampling, you can change the 'Foreground/Background Jitter' control to 'Pen Pressure' and then lay down a blend of colors using both the foreground and background color:

3.) Simulating Real-World Brush Sizes

A nice trick I learned from a forum post by John Derry is how to simulate the size of real-world brushes in Photoshop (and any other program for that matter). Basically, to simulate real-world brush sizes, you merely have to relate them to the pixel resolution of your image. So, if you're painting in a 300dpi image (a standard resolution for printing), a 300-pixel brush would equate to a 1-inch brush in the real-world (300dpi = 300 pixels per inch). Likewise, a 150-pixel brush would be a 1-inch brush in a 150dpi image (an acceptable resolution for inkjet printing).

Considering that the Mixer Brush is meant to simulate real-world paint blending, you might find it more comfortable working with brush sizes you're familiar with.

4.) Start Small

Unless you have a state-of-the-art computer, you've probably noticed that Photoshop's new Mixer Brush requires considerable processing power. To make matters worse, when combined with Photoshop's new Bristle Brushes, the Mixer Brush can bring your computer right down to it's knees. For this reason, I recommend starting small (150dpi or less) before finishing your painting at a higher resolution.

Working at a lower resolution will allow you to block in large areas with big brushes without experiencing too much of a performance hit. And you can simply increase the resolution of your image as you begin to refine and add details.

I find that 150dpi works for my particular system. If I need more detail, I bump the resolution up to 300dpi.

5.) Sharpen to Improve Details

Painting in Photoshop sometimes results in a 'soft' painting, especially when using the Mixer Brush. Details end up blurry, and brush strokes lose their definition. To help bring back detail and make the image 'pop', I often use the 'Unsharp Mask' filter (a staple for photographers).

Found in the 'Filter>Sharpen' menu, 'Unsharp Mask' enhances details by increasing contrast along edges it finds in the image. The size of the edges found is determined by the 'Radius' setting. Basically, to enhance textures and small details, use a low radius setting. To enhance the contrast of large features, use a higher radius setting. The 'Amount' controls the amount of sharpening applied. 'Threshold' helps protect smoother areas from being sharpened (like skin texture) when you only want edges to be sharpened.

Generally, you'll only want to use radius values between '0.5' and '2' depending on the resolution of your image. For paintings, I rarely ever use a threshold setting higher than '0' because I want textures and brush strokes to be enhanced as well as details.

(If you want to selectively apply an 'Unsharp Mask' to certain areas of your painting, you can duplicate the painting onto a new layer, then sharpen and apply a Layer Mask to the duplicate. Paint out the Layer Mask with white to selectively sharpen areas by revealing the sharpened duplicate.)

6.) Pump Up the Colors

Mixing colors in any medium can sometimes result in a muddy painting. And mixing colors with Photoshop's new Mixer Brush is no exception. Thankfully, adjusting colors in Photoshop is a snap using Photoshop's many Adjustment Layers.

Some of the most useful Adjustment Layers for painting include Levels, Curves, Hue/Saturation, Color Balance, Brightness/Contrast, and Vibrance. For the sake of this article, however, I'll only discuss the Brightness/Contrast and Vibrance adjustment layers, since both have been improved in recent versions of Photoshop and now represent the easiest way to enrich the colors of an image.

In older versions of Photoshop, using the Brightness/Contrast adjustment layer was generally frowned upon because it clipped colors, unlike the more advanced Curves adjustment layer. This problem has been fixed in recent versions of Photoshop, and Brightness/Contrast now provides a quick and easy way to punch up the contrast in an image, enriching colors slightly in the process.

Similarly, the Vibrance adjustment layer was added to Photoshop to address the problems of color clipping caused by the Hue/Saturation adjustment layer. The new Vibrance slider increases color saturation with minimal color clipping and now provides perhaps the best way to increase color saturation in an image.

Combined, the Brightness/Contrast and Vibrance adjustment layers represent a quick and easy way to pump up colors which may have gone muddy while painting with Photoshop's new Mixer Brush.

Conclusion:

In summary, this is the summary. ;-P Who needs conclusions anyway if you read the article?

Thanks for reading! =)

Photoshop CS5 Mixer Brush Tips and Tricks

(This is the first of two articles on the Mixer Brush that I've written.
The second can be found here.)

Having wrestled with Photoshop's new Mixer Brush in CS5 for the past few months, I've come to the conclusion that the new tool is indeed a great addition, however with many caveats.  Some of the problems are technical ones (such as painting in 8-bits/channel), others by design (not mixing with transparency).

Here are the biggest hurdles I've come across while working with the new Mixer Brush, and how I've overcome them for the time being.

1.)  Paint in 16-bits/channel.

This one stumped me for a long time.  No matter how intense my color choices, the Mixer Brush always seemed to produce muddy results.  The problem lay in the fact that the Mixer Brush wasn't actually painting with the color I had selected in the Color Picker.  Not until tackling an unrelated problem did I finally find the solution - the Mixer Brush only works properly in 16-bits/channel.

As can be seen in the pic below, the Mixer Brush never manages to build up to the actual color you have selected when painting in 8-bits/channel, no matter how many strokes you lay down.

When painting in 16-bits/channel, the Mixer Brush works just fine.

So the solution is easy - paint in 16-bits/channel!  To change any document to 16-bits/channel, select 'Mode>16 Bits/Channel' in the 'Image' menu.  You can also set the color depth in the 'New Document' dialog when creating a new document.

The only problem with this solution is that not all filters are available when working with 16-bit images, so expect to change the mode occasionally if you like using filters.

2.)  Paint in a wide-gamut RGB space or in Lab Color mode.

This is an optional but recommended solution to the limited color palette of Photoshop's default sRGB color space.  I mention this as an optional solution because the Mixer Brush, like real oil paint, can sometimes produce muddy results. Being able to pick more intense and saturated colors can help alleviate this problem.  I'm hesitant to discuss this issue too deeply however as it would require an explanation of color management, which is a headache for anyone.  Suffice it to say, even Adobe recommends working in Adobe RGB at the least.

If you do decide to try working in a wide-gamut RGB, or in Lab mode, don't forget to convert back to sRGB if you plan on displaying your image on the web.

(I'll discuss this point in finer detail in a future article.)

3.)  Use 'Copy/Paste Merged' instead of 'Sample All Layers'.

The 'Sample All Layers' feature of the Mixer Brush allows you to blend colors on a new layer, preserving color information on other layers.  Unfortunately, this feature also tends to slow down brush interaction dramatically.

I recommend using the 'Copy/Paste Merged' command (shortcut Ctrl+Shift+Alt+E) instead to copy the contents of all underlying layers onto a new layer.  This will allow you to paint on a copy of the other layers.  You can then adjust the opacity of the new layer and merge down when finished.  (If you have only one layer in the image, just duplicate the layer by dragging it down to the new layer button in the Layers Palette.  The 'Copy/Paste Merged' shortcut only works if more than one layer is present in the document.)

There really isn't any advantage to the 'Sample All Layers' feature other than reducing file size - a 'fringe' of color is created around your brush strokes, making most layer blend modes other than 'Normal' practically useless.  (It is possible to use many other layer blend modes with the Mixer Brush, however, as I explain in the next point.)

If you wish to 'Copy/Paste Merged' only certain areas of an image, you can select an area with the marquee tools and then manually select 'Copy Merged' and 'Paste' from the 'Edit' menu.

4.)  Using Layer Blend modes and blending with Transparency.

One of the major drawbacks of Photoshop's new Mixer Brush is that it doesn't blend with transparency, making the process of painting on layers a bit of a hassle.  Instead, Adobe opted for the 'Sample All Layers' feature discussed above.

However, the Mixer Brush can fake blending with transparency just fine using most layer blend modes, provided the layer is filled with the appropriate 'neutral' color.  A 'neutral' color is any color which appears transparent when using a certain blend mode.

Most layer blend modes have an associated neutral color, which (when filled with that color) will blend with the Mixer Brush as if the brush were blending with transparency.

To easily fill a new layer with a neutral color appropriate to it's blend mode, hold 'Alt' while pressing the 'New Layer' button in the Layers Palette.  In the 'New Layer' dialog, select a blend mode.  If that blend mode has a neutral color, the option to fill the layer with that color will become active.  Simply select the option to fill the layer and then click 'OK'.

I find that using Actions to create layers with blend modes I use often can save a lot of time. You can also fill the layer with it's neutral color, color code the layer, and name the layer all in one action (such as creating a blue layer named 'Multiply Layer').

For easy reference of Layer Blend modes and their respective neutral colors, I created this chart:

5.)  Set a shortcut key for Loading/Unloading Color.

The Mixer Brush also makes a great blending brush.  Normally, to turn the Mixer Brush into a straight blending brush you have to toggle off the 'Auto-Load' button in the Tool Options Bar.  However, a shortcut key can be assigned to make the task quicker.

In the 'Tools' section of the 'Keyboard Shortcuts' dialog box (opened by selecting 'Keyboard Shortcuts...' in the 'Edit' menu) select 'Toggle Mixer Brush Auto-Load' near the end of the list and then set a shortcut key:

Now the Mixer Brush can be toggled from a paintbrush to a blending brush simply by pressing that key.

6.)  Use Scatter Count settings to strengthen Bristle Brushes.

The new Bristle Brushes in CS5 are a great addition, expecially if you have a Wacom tablet and a rotation-sensitive Art Pen.  Adjusting them for use with the Mixer Brush can be tricky however, especially if you want a bolder stroke without too much bristle thickness.

One way I've found to increase brush opacity (while keeping bristle thickness to a minimum) is to increase the Scatter Count of the brush.

A Count setting higher than '2', though, might slow down your brush's interaction, so be careful when using this option.

7.)  The Wetness slider works better with Non-Bristle Brushes.

Although the new Bristle Brushes in CS5 work fairly well with the new Mixer Brush, I've found that the Wetness property of the Mixer Brush works far better with normal brush types.  At low settings, the Wetness slider still has a very wet effect with many Bristle Brush settings.

For this reason, it's still worth your time to try using the Mixer Brush with regular brush types if you want a subtler blending effect.

8.)  Height Textures can add greater pressure-sensitivity.

While the Mixer Brush lacks an opacity setting, experimenting with Height Textures can add a great deal more subtlety to your strokes.

By setting the Brush Texture mode to 'Height' and the 'Depth Jitter Control' to 'Pen Pressure', you can simulate how real paint interacts with the grain of your canvas; the heavier the stroke, the greater the penetration.

Using very low 'Depth' settings, you can effectively simulate drybrushing.  And by inverting the texture, you can simulate thin paint puddling into the grain of the canvas.

The only problems I've found with adding a Height Texture to a brush are a slight performance hit, and the fact that the settings seem to vary their effect slightly if you change the brush's original size by a large amount.

9.)  Using a Round Brush with the Mixer Brush.

If you prefer using round brushes for your painting, then you've probably noticed that they don't work very well with the new Mixer Brush.  I've found that certain brush settings and brush presets can help alleviate the problem, however.

First, to prevent stepping, Brush Tip Shape 'Spacing' should be set relatively low (preferably 5% or lower):

The real problem, though, has to do with the default round brush's Tip Shape.  The default round brush has a completely black Tip Shape, meaning you'll have a hard time laying down light strokes since the Mixer Brush has no opacity setting.  You could lower the Flow setting but I've found this can produce undesirable color shifts and doesn't allow you to mix to full color in a single stroke.

The solution I've found is to make lighter Brush Tip Shapes, like the one shown below:

Of course, the downside to this method is that you won't be able to change brush hardness unless you make several versions at various levels of hardness, since only the default Photoshop round brush can change hardness using a slider.

Conclusion:

Though I've had a heck of a time making the new Mixer Brush in Photoshop CS5 work for me, I feel that I've successfully tackled most of the issues which plagued me at the start.  Hopefully, Adobe will address many of these issues in the next version of Photoshop, especially the ones dealing with transparency, color depth, and bristle brush wetness.

For more tips on using the Mixer Brush, see my follow-up article: More CS5 Mixer Brush Tips.

Thanks for reading! :)

p.s. Eventually, I plan to make some of the brushes I've made with the Mixer Brush available for download.  I just need to find a suitable (and preferably free) webhost first.

For those interested, John Derry has a set available for purchase.