Contents
An Introduction to Photoshop’s History Brush Tool
How to Use Photoshop’s History Brush Tool
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How to Use Photoshop’s History Brush Tool
Using Photoshop’s History Brush tool involves four main steps:
- Edit the image.
- Select a History state.
- Adjust the History Brush tool’s settings.
- Paint with the History Brush.
Step 1: Edit the Image
Since the effects of the History Brush tool depend on the steps you’ve already taken in editing your image, it’s crucial that you make the right edits in order to get the effect you desire. The most common use of the History Brush tool involves restoring color to parts of an image that you previously converted to black and white. This guide covers this entire process, including the initial conversion to black and white, through the example of converting a sample image of a cat to black and white and then using the History Brush tool to return color to the cat’s eyes. If you want to use the History Brush tool for some other purpose, such as selectively applying filters, you have to make those edits before you can use the History Brush tool.
The specific editing steps to edit a color image and convert it to black and white are
as follows:
- Open the image: Open the image in its full-color, unmodified state.
- Make basic edits: Perform edits such as cropping, resizing, and so on.
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Convert the image to black and white: To do a simple black-and-white conversion, click Image > Mode > Grayscale. If you’re using Photoshop CS3, you can use the new Black and White conversion feature by clicking Image > Adjustments > Black & White. A dialog box will appear in which you can preview and fine-tune the conversion.
How to Use Snapshots to Save History States When Editing
At any point while you’re editing an image in Photoshop, you can take a snapshot of the
image in its current state. Photoshop stores that snapshot in the History palette. You can then return to that snapshot at any point, regardless of how you modify the image after taking the snapshot. You can also use those snapshots as History states when working with the History Brush tool.
Using snapshots can come in handy if you want to experiment with a few different looks when applying the History Brush tool. For example, if you wanted to restore color to a photo that you converted to black and white and try the same effect on a sepia-toned version of the image, you could do so by following these steps:
- Create a sepia-toned version of the image.
- Take a snapshot of the image in its sepia-toned state.
- Return the image to its pre-sepia state by using the Undo command (Ctrl+Z on a PC or Command+Z on a Mac).
- Convert the image to black and white.
- Use the snapshot you created in step 2 as your History state and apply the History Brush tool to see how the color would look against a sepia-toned version of the image.
- Undo that change.
- Use the History state just before you converted the image to black and white (step 3) and apply the History Brush tool to see how the color would look against a black-and-white version of the image.
How to Take Snapshots
To take and store a snapshot, click the camera-shaped snapshot icon at the bottom of the History palette. Photoshop will store each snapshot you take as an entry near the top of the History palette just under the entry for the original image, as shown in the sample History palette included here. You can then click the checkbox next to the description of the snapshot to use that snapshot as a History state, as explained in Step 2 below.
Step 2: Select a History State
Think of the History state you select as a point of reference for the History Brush tool. By choosing that specific state, you’re telling the History Brush tool to restore the areas you paint to the way they were up to and including that state. So, for example, if you want to restore color to certain parts of an image you’ve converted to black and white, you should choose the History state immediately prior to the step in which you converted the image to black and white.
To select a specific History state, click the box immediately to the left of the description of the state (or snapshot). The History Brush tool’s icon will then appear in whichever box you check.
Step 3: Adjust the History Brush Tool’s Settings
The History Brush toolbar contains five settings that you can set to affect how using the history will modify the photo you’re working on: Brush, Mode, Opacity, Flow, and Airbrush.
The Brush Setting
To select a Brush setting, click the tiny arrow to the right of the brush icon in the toolbar. The brush settings drop-down menu will open. The drop-down menu contains two settings (Master Diameter and Hardness) as well as a selection of various brush tips.
- Master Diameter: This setting determines the size (diameter) of brush tip. The Master Diameter setting is measured in pixels (px), ranging from 1–2500px. The specific pixel setting that you should choose depends on the size of the image you’re editing and the size of the area that you’d like to target with the History Brush tool. Choose a size that will allow you to paint your target area as easily and efficiently as possible. So, for instance, to paint the cat’s eyes in the sample image, you’d choose a brush with a diameter small enough to allow you to paint within the eyes without spilling over into the areas surrounding the eyes. Note that you can also change the Master Diameter setting on the fly as you edit by using the bracket keys (press “[“ to make the brush diameter smaller, and “]” to make it larger).
- Hardness: The Hardness setting lets you specify what percentage of the brush’s tip should be hard as opposed to soft. Settings range from 1–100% (lowest to highest). Harder brushes paint more precisely than softer brushes but do so with a “hard,” or well-defined, edge around the brush’s perimeter. A high hardness setting is typically best when using the History Brush tool to target specific areas of an image with precision. You might choose a lower hardness setting to make the History Brush’s effects softer, or more diffuse. In the sample image, you’d want to use a setting of 100%, in order to target the pixels in the cat’s eyes as precisely as possible.
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Brush tips: The bottom portion of the brush settings drop-down menu contains a scrollbar that lets you browse through dozens of different brush tips, each with its own shape and character. To the right of each tip, you’ll also see an example of each brush’s stroke. Choose a brush tip that makes it as easy as possible for you to target the areas you want to paint with the History Brush. For instance, if you’re aiming to restore color to a black-and-white photo, choose a brush with a standard circular shape that will make it easy to target the areas that you’d like to colorize.
The Mode Setting
The Mode setting lets you specify a blending mode to use when applying the History Brush tool. Photoshop’s blending modes are settings that determine how the existing pixels in an image are affected when a painting tool or an editing tool is applied to those pixels. Blending modes are an advanced Photoshop concept that you don’t need to understand fully in order to use the History Brush tool effectively. As a beginner, you’ll get satisfying results with most
images simply by skipping this step and leaving the blending mode set to Normal.
The Opacity Setting
The Opacity setting determines the transparency of the effects that the History Brush tool applies. Settings range from 1–100%. A 100% setting makes the effects of the brush entirely opaque. A lower setting makes them partly or completely transparent—the brush’s effects will blend with the image as it currently appears. Note that you can change the opacity setting at any time while using the History Brush tool simply by entering numbers on the keyboard. So to switch the opacity setting to 77%, for instance, you’d just type 77.
The Flow Setting
The Flow setting sets the rate at which the brush applies paint. Settings range from 1–100%. A 100% setting makes the brush’s paint appear at the opacity setting you’ve set immediately, whereas a lower setting makes the paint flow more slowly until it ultimately reaches the same opacity setting. For instance, if you have the opacity set to 50% and the flow set to 100%, the paint you apply will immediately appear at 50% opacity. If you have the opacity set to 100% and the flow set to 50%, it will take a few seconds of holding down the mouse button for the paint to reach 100% opacity. No matter which flow setting you choose, the paint that the brush applies will never exceed the maximum opacity you’ve set. Unless you’re creating an illustration from scratch in Photoshop, it’s generally best to leave the flow setting at 100%.
The Airbrush Setting
At the far right end of the History Brush toolbar is the icon for the Airbrush setting . Clicking this icon turns on the brush’s airbrush feature. The airbrush feature makes the brush (and its effects) softer, or more diffused. Think of it as a quick way of setting the brush’s Hardness to a low setting. Though turning on the airbrush won’t actually change the Hardness setting, it will deliver effects similar to using a soft brush.
Step 4: Paint with the History Brush
Once you’ve made your edits, clicked on the right History state in the History palette, and chosen brush settings, you’re ready to start painting with the History Brush. Paint with the brush exactly as you would with any other Photoshop brush, but just be extra-careful to paint only in the areas that you’d like the History Brush to modify. As you paint, you’ll see the version of the image from the History State you clicked on in Step 2 reappear, as shown here in the sample image. Continue painting until you’ve covered all of the areas that you want to modify with the History Brush.
Switching the Color Space Before You Paint with the History Brush Tool
Color spaces, such as RGB, Grayscale, and CMYK, determine the range of colors in an image. When using the History Brush tool, you’ll often switch between color spaces. For instance, in converting your color image to black and white, you switched from the RGB color space to Grayscale. Whenever you use the History Brush tool to restore parts of an image from a History state in which a different color space was active, you’ll first need to switch back to that color space. So, to restore RGB color to an image that you converted to black and white, for example, you’d first need to reactivate the RGB color space. To do so, click Image >
Mode > RGB Color. If you forget to make this switch before trying to apply the History Brush tool, a popup message will appear to remind you to switch color modes.
If You Make a Mistake While Painting with the History Brush Tool
It’s a good idea to let go of the mouse button after every stroke you use to paint with the History Brush. Each time you do, Photoshop saves your latest stroke in the History palette—so if you make a mistake, you can always step back through your History to undo as many strokes as needed in order to fix the error. You can then paint over the area again, repeating the process until you make no mistakes.
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