| • | To paint in a channel |
| • | To apply an effect to a channel |
| • | To feather a channel |
| • | To invert a channel |
| • | To fill a channel with a pattern |
| • | To fill a channel |
You can edit a channel by modifying the size, shape, or opacity of its protected area, which ultimately becomes the protected area of the selection. The changes that you make to the channel do not directly affect the image until you load it as a selection. For more information, see To load a selection from an alpha channel.
You can apply changes by selecting a brush and painting the changes in the channel.
A channel before and after feathering
You can also invert a channel to convert a protected area into an unprotected area.
A channel before and after inversion
In addition, you can introduce interesting effects by filling a channel with a pattern, gradient, or weave. For more information, see Working with color fills.
| To paint in a channel |
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| 1 . | In the Channels panel, display and select the channel you want to work with. |
| If you want to paint only on a specific area of the channel, make a selection. |
| 2 . | Choose the Brush tool  from the toolbox. |
| 3 . | Click the Brush Selector on the Brush Selector bar. |
| 4 . | In the Brush library panel, click a brush category, and brush variant. |
| The Pen and Airbrush brush categories make good choices. |
| 5 . | In the Color panel, choose one of the following: |
| • | Black — adds to the protected area |
| • | White — removes from the protected area |
| • | Grey — applies a semi-protected area |
| When you paint in the channel, hue is irrelevant. The channel carries 8 bits of information and you need only set a level in that range. The value scale is between black and white. |
| 6 . | Paint in the document window. |
| 7 . | In the Channels panel, click the eye icon  next to the RGB channel’s thumbnail to display the channel in grayscale. |
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Adjust the Opacity slider on the property bar.
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Type a value in the Size box, or adjust the slider.
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| To apply an effect to a channel |
|
| 1 . | In the Channels panel, display and select the channel you want to work with. |
| If you want to apply the effect to a specific area of the channel, make a selection. |
| 2 . | Choose an effect from the Effects menu. |
| To feather a channel |
|
| 1 . | In the Channels panel, display and select the channel you want to work with. |
| 2 . | Click the Channel options button  , and choose Feather. |
| 3 . | In the Feather dialog box, type a number of pixels. |
| To invert a channel |
|
| 1 . | In the Channels panel, choose a channel from the list. |
| 2 . | Click the Invert Channel button  . |
| To fill a channel with a pattern |
|
| 1 . | In the Channels panel, display and select the channel you want to work with. |
| If you want to fill only a specific area of the channel, make a selection. |
| 2 . | Click Window  Media Panels Patterns. |
| 3 . | In the Patterns panel, click a pattern swatch. |
| 4 . | Choose Edit Fill. |
| 5 . | In the Fill dialog box, choose Original Luminance from the Fill with list box. |
| If you want to change the opacity, adjust the Opacity slider. |
| To fill a channel |
|
| 1 . | In the Channels panel, display and select the channel you want to work with. |
| 2 . | Choose the Paint Bucket tool  from the toolbox. |
| 3 . | On the property bar, click the Fill Image button  . |
| 4 . | From the Fill list box on the property bar, choose one of the following: |
| • | Current Color — fills with the current color (a shade of gray). For information, see Working with color fills. |
| • | Gradient — fills with the selected gradient. For information, see Applying gradients. |
| • | Source Image — fills using the current clone source image. If you haven’t defined a clone source, Corel Painter fills with the current pattern. For information, see Filling an area with a sampled image. |
| • | Weave — fills with the selected weave. For information, see Applying weaves. |
| 5 . | Open the Fill selector on the property bar, and click a swatch from the media library panel. |
| 6 . | Click the area of the channel you want to fill. |
| If the result is not what you want, undo the fill, change the settings, and try again. |
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On the property bar, type a value in the Tolerance box, or adjust the slider.
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On the property bar, type a value in the Feather box, or adjust the slider.
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Enable the Anti-Alias button
 on the property bar. Anti-aliasing is desirable when Feather is zero or extremely low. |
The Paint Bucket tool applies a fill only to a visible channel. Make sure the channel’s eye icon is open before using the Paint Bucket tool.
You can return to the default Paint Bucket tool settings by clicking the Reset Paint Bucket Tool button 
on the property bar.
