Photoshop Brush Tutorial: Brush Tool Options

Let's begin our look at Photoshop's Brush tool by exploring the various options we have at our disposal for the Photoshop brushes.

As usual, all of the options for the Brush tool can be found in the context-sensitive Options Bar at the top of the screen, directly below the Menu Bar. If you don't already have the Brush tool selected, go ahead and select it now from the Tools palette. It's the icon that looks like, well, a paint brush (fourth one down from the top in the right-hand column). You can also press B on the keyboard to select the Brush tool, which is the more efficient way of selecting it.

If you don't see the Brush tool icon where it's supposed to be in the Tools palette, it's because you had the Pencil tool selected previously (or the Color Replacement Tool if you're using Photoshop CS2), in which case the Pencil tool icon (or Color Replacement Tool icon) is displaying in the Tools palette where the Brush tool icon normally would be. If that's the case, simply click and hold your mouse down on the Pencil tool (or Color Replacement Tool) icon for a second and a pop-out menu will appear, allowing you to select the Brush tool, which will appear at the top of the list.

Now that you have the Brush tool selected, the options for the Brush tool will be displayed in the Options Bar at the top of the screen. Let's look at each option, starting from the left and working our way to the right.

The Tool Preset Picker

The Tool Preset picker in the Brush Tool Options Bar, which was added in Photoshop 7, is where we can save and retrieve tool presets. The main difference between Photoshop's Tool Preset picker and Brush Preset picker is that the Tool Preset picker can store presets for any and all of Photoshop's tools, and you can retrieve any tool preset at any time, regardless of which tool you currently have selected. With the Brush Preset picker, you can select only brush presets, and you must have the Brush tool selected in order to access the Brush Preset picker.

The Brush Preset Picker

The Brush Preset Picker is where we can access all the brushes that load with Photoshop by default, as well as any brushes we've created ourselves. A scroll bar in the bottom half of the dialog box allows us to scroll through a list of the brushes, complete with the size of the brush tip in pixels, the shape of the brush tip, and a sample of what the brush will look like when we paint a brush stroke with it.

If you click the right-pointing arrow in the top right corner of the Brush Preset Picker dialog box, a list of options will appear. From this list, you can:

• Create a new Brush Preset
• Rename or delete existing brushes
• Change the way the brush preview box in the Brush Preset Picker dialog box displays the brush previews
• Access the Preset Manager
• Load and save additional brush presets
• Reset the brushes to Photoshop's default brushes
• Replace the existing brushes with other brush sets
• and choose from a list of other brush sets which Photoshop comes with.

We can also change the size of a brush by dragging the Master Diameter slider left and right, and with Photoshop's standard round brushes, we can change the Hardness of the brush, again by dragging the slider.

* Note that there are basically two types of brushes in Photoshop. There's Photoshop's standard round brushes which can have hard or soft edges, and then there are sampled brushes. You can tell the sampled brushes because they look like interesting shapes rather than standard circles. The sampled brushes can only have hard edges. Photoshop doesn't give you the option to soften their edges, which is why the Hardness option in the Brush Preset Picker dialog box is grayed out when selecting a sampled brush.

Also, while Photoshop's standard round brushes can be resized from 1 pixel all the way up to 2500 pixels, this is not the case for sampled brushes. Well, I shouldn't say that. Technically, Photoshop does give you the option to increase the size of sampled brushes up to 2500 pixels, but from an image quality standpoint, you don't want to increase the size of a sampled brush much beyond its stated sample size, otherwise those crisp, sharp edges of the brush tip will start to become soft and blurry. For example, if a sampled brush has a sample size of 63, that means it was sampled at 63 pixels, which is the largest you can make it before the edges will start to look soft and blurry. You can make the brush smaller than the sampled size without any loss of quality, but the larger you make the brush beyond its sampled size, the softer and blurrier the brush will appear. You can quickly set the brush to its actual sampled size in the Photoshop Brush Preset picker by clicking the "Use Sample Size" button (which is only visible when you have a sampled brush selected)..

The Painting Modes

If you've used Photoshop before, you may have noticed a drop down box in the Layers palette which contains a list of blend modes for the layer, such as "Normal", "Screen", "Multiply", and "Overlay". These options are called "blend modes" because they affect how the layer you currently have active will blend in with the layers beneath it.

The same can be said about the blend modes found in the Options Bar for the Brush tool. For the most part, these are the exact same blend modes as what you'll find in the Layers palette, with only a couple of exceptions which we'll look at in a moment. These blend modes for the Brush tool, which are referred to as "paint modes" rather than "blend modes" when associated with brushes, affect how the color you're painting with will blend in with the existing colors on the layer you're painting on.

The main difference between the "paint modes" of the Brush tool and the "blend modes" of the Layers palette is that layer blend modes affect how a layer blends in with all the layers beneath it, whereas the paint modes of the Brush tool affect only the layer you're painting on. They have no effect on any other layer.

As I said a moment ago, the paint modes for the brushes are the same as the layer blend modes, with two exceptions:

Behind: The Behind paint mode, which is not found in the Layer blend modes, only works on layers with either transparent or partially transparent areas. The color that you're painting with only shows through on areas that are transparent or translucent, giving the illusion that you're painting behind whatever image is on the layer already, even though you're painting on the exact same layer.

Clear: The Clear paint mode, also not found in the Layer blend modes, essentially turns your brush into an eraser, clearing away any pixels you paint over. The Clear option is only available on layers other than the Background layer, since erasing pixels from the Background layer would create transparent areas and Photoshop doesn't allow transparency on Background layers.

The Opacity Slider/Selection Box

Moving along from left to right in the Options Bar, we find the Opacity option. Opacity affects the transparency of your brush. A value of 100% makes your brush fully opaque (i.e. you can't see through it at all) while a value of 1% makes it so transparent you'll barely be able to see it. A value of 50% will make your brush 50% transparent.

The quickest and easiest way to change the value inside the Opacity box is to simply type a number value on your keyboard, and presto! The value is added to the Opacity option. That's assuming that you don't have the Airbrush button selected over on the right of the "Flow" option, which we'll look at a bit later. If you have the Airbrush option selected and you type a number on your keyboard, the value you typed will be added to the Flow option box rather than the Opacity box. So, to quickly change the value of the Opacity option, just type a number on your keyboard with the Airbrush option deselected.

To change the value to something like "10%" or "50%", simply type the first number and Photoshop will automatically add the "0" after it. However, if you need to type a value such as "55%" or "16%", all you need to do is type both numbers quickly one after the other. To enter in a single digit value such as 7%, type "0" and then quickly type "7". For a value of "100%", simply type "0". These same rules apply to changing the Flow value as well, although you need to have the Airbrush option enabled for the values you type to affect the Flow option box.

* Quick trick: To quickly enable or disable the Airbrush option, press Shift+Alt+P (Win) or Shift+Option+P (Mac) on the keyboard.

There's a couple of additional ways to change the value of the Opacity option, and these also apply to the Flow option. You can click on the blue, right-pointing arrow beside the value box, which will bring up a small slider bar which you can click on and drag left and right to increase and decrease the value. That's one way. The other way, which is much more fun, is to simply click and hold your mouse down directly over the word Opacity (or Flow), which will bring up what is affectionately known as a "scrubby slider", allowing you to "scrub" the value up and down by dragging left and right with your mouse. Scrubby sliders were first introduced in another of Adobe's software products, "After Effects", and now, as of Photoshop CS, we get to enjoy them as well.

The Flow Slider/Selection Box

A lot of people are confused when it comes to the difference between "Opacity" and "Flow", and it's not hard to see why. However, they really are two completely different things, although Flow is somewhat related to Opacity.

What "Flow" does is control how much paint your brush puts down when you paint over an area with your mouse, which technically is exactly what Opacity does, hence the confusion. The difference though between Opacity and Flow is that with Opacity, as long as you don't lift your finger off the mouse and then click again to continue painting, your brush will add exactly the amount of "paint" you've specified in the Opacity value, and no more. No matter how many times you paint over the same area, as long as you don't lift your finger off the mouse and then click again to continue painting, your brush will never add more paint.

With Flow, that's not the case. If you have a value of 10% specified for Flow, the first time you paint over an area, you'll lay down 10% of your paint. But here's the difference. The next time you move your mouse over the same area, you'll add another 10% on top of the original 10%, even if you haven't lifted your finger up off the mouse. Paint over the same area again, and yet another 10% will be applied. That's the difference between Opacity and Flow. Opacity keeps the paint % value the same no matter how many times you paint over the same area (with the mouse button still down), while Flow increases the amount of paint in an area by the % value every time you pass the mouse over the same area.

If you're not confused yet (and hopefully you're not but if you are, the easiest way to see the difference between Opacity and Flow is to experiment and try them out on your own), here's one final thing you need to know about Flow. Flow is limited by the value you've set in Opacity. What I mean by that is, Flow can never, no matter how many times you paint over the same area, never ever add more paint than the value you've specified for Opacity. In other words, if you've set an Opacity of 50% and set Flow to 100%, Flow will only add 50% of the paint to the canvas because it's limited to 50% by the Opacity value. It can't go beyond that. You can paint over the same area until the cows come home but if you're Opacity value is set to something less than 100%, Flow can only add paint up to the % value you've specified for Opacity.

If you're now completely confused about the difference between Opacity and Flow, like I said, the easiest way to see the difference is to simply grab a brush, pick a color, change the value in Opacity and start painting. Then change the value again and paint again. Once you're comfortable with what the Opacity value is doing, set Opacity to 100% and start changing the Flow value while you paint. It won't take long before the difference between the two becomes clear.

Again, there's several ways to change the value in the Flow option box, which are all exactly the same as they are for the Opacity option, so I won't bother repeating them here. Simply check them out in the description of the Opacity option above if you haven't already.

The Airbrush Selection Button

Our final option for the Brush tool up in the Options bar is a little icon that looks like, well, like an airbrush, which enables and disables airbrush capabilities for our brush. The airbrush used to be its own tool in the Tools palette, but Adobe decided with Photoshop 7 that it makes more sense to have it as an option for the brushes rather than it being completely separate tool, so they moved the airbrush up into the Options Bar where it remains though to Photoshop CS2.

You've probably heard the term "airbrushed" before, usually from someone complaining that the super model on the cover of the latest fashion magazine doesn't really look like that in real life. "She's obviously been airbrushed", they'd say, and they'd most likely be correct in saying that. However, this isn't a discussion about the harmful effects of the fashion industry on our impressionable youth or anything like that, this is about the airbrush option in Photoshop's Options Bar, and what the Airbrush option does is, when enabled, puts down a continuous flow of paint, even if you're not moving your mouse. As long as you have the mouse button pressed, with the Airbrush option enabled, the brush will continue putting down paint, at a speed rate that's determined by the value you've entered in the Flow option, and again, only up to a maximum percentage of what you've specified in the Opacity option.