Using Gradients

A gradient is a gradual transformation from one color into another. Sometimes they are called blends or fountains. Corel Painter provides several different types of gradients: linear, radial, circular, and spiral.

Examples of gradient types, from top to bottom: linear, radial, circular, and spiral.

You can use gradients to:

• Fill an image selection, layer, or channel. For more information, see "Using Selections", "Using Layers and Layer Masks", and "Using Alpha Channels".
• Control a Pop-Art Fill effect. (Other effects work best when you use a filled mask.) For more information, see "Pop Art Fill".
• Express the gradient in an existing image by mapping gradient colors to image luminance. For more information, see "Creating Texture Using Image Luminance".
• Brush with a gradient with one of the computed brushes (using one of these dab types: line airbrush, projected, or rendered). For more information, see "Dab Types".

Although Corel Painter comes with libraries full of gradients, you'll invariably want to create some of your own. To do that, you just need to define two colors and create a gradient between them.

You can also capture gradients from existing images or create your own libraries of gradients. Use the options on the Gradients palette to select and adjust Corel Painter gradients.

Gradients are stored in libraries. You can load alternate libraries of gradients to increase your choices. For more information about working with libraries, refer to "Loading Alternate Libraries".

The Gradient selector on the Gradients palette.

To select a gradient

1. Choose Window menu > Show Gradients to display the Gradients palette.

If the Gradients palette is not expanded, click the palette arrow.

2. Click the Gradient selector and choose a gradient style.
3. Click one of the Gradient Types on the right of the palette to select between the four types of gradients-linear, radial, spiral, or circular.

The Preview window shows how current settings affect a selected gradient.

To change gradient order

1. Choose Window menu > Show Gradients to display the Gradients palette.
2. Click one of the Gradient Orders at the bottom of the palette to determine how the gradient behaves:

• left to right
• left to right and mirrored
• right to left
• left to right and doubled
• right to left and mirrored
• right to left and doubled

The Preview Strip (above the gradient orders) shows the selected gradient order.

Examples of gradient orders.

To change a gradient angle

1. Choose Window menu > Show Gradients to display the Gradients palette.
2. Drag the red ball in the gradient angle ring, or click once anywhere on the ring to change the gradient angle.

A corresponding numeric value appears below the gradient preview.

To change spiral tension

1. Choose Window menu > Show Gradients to display the Gradients palette.
2. Do one of the following:

• Hold down Command (Mac OS) or Ctrl (Windows) while you drag the red ball in the gradient angle ring to change how tightly wound the spiral gradient becomes.
• Click inside the gradient preview to cause Corel Painter to rotate the gradient for you.

Click anywhere outside the preview to stop the rotation.

Creating and Editing Gradients

You can create from very simple to very complex gradients. For a simple two-point gradient, you just need to choose a primary and a secondary color, then have Corel Painter create a gradient between them. For more complex gradients, use the Gradient Editor or capture gradients from existing artwork. Color control points in the Gradient Editor are used to control at which point a new gradient starts.

You can save gradients and use them to fill a selected object. For more information on filling an object, refer to "Filling Techniques".

To create a two-point gradient

1. Choose Window menu > Show Colors to display the Colors palette.
2. On the Colors palette, click the primary color rectangle and choose a primary color.
3. Click the secondary color rectangle and choose a secondary color.
4. Choose Window menu > Show Gradients.
5. Choose Two-Point from the Gradient selector.

• When creating a two-point gradient, set a color for the right control point, and then set a color for the far left control point.

• You can also select colors in between the end colors to create interesting gradient effects.

To edit or create a complex gradient

1. Choose Window menu > Show Gradients to display the Gradients palette.
2. Click the palette menu arrow, and choose Edit Gradient.

The colored ramp across the top of the Edit Gradient dialog box displays the current gradient. The pointed gray markers along the bottom of the bar are color control points. You can position these pointed markers to change the color of the blend at individual gradient points.

3. Click a color control point to select it.
4. On the Colors palette, click the primary color rectangle and choose a primary color.
5. Repeat steps three and four for each color control point you want to edit.

Use the Edit Gradient dialog box to create or edit gradients.

To add color control points

1. Choose Window menu > Show Gradients to display the Gradients palette.
2. Click the palette menu arrow and choose Edit Gradient.
3. In the Edit Gradient dialog box, click anywhere in the color ramp bar.

The control point is added, without affecting color.

4. Click the new color control point to select it.
5. Open the Colors palette and choose a color.

• You can press Option + click (Mac OS) or Alt + click (Windows) in the bar to both create a control point and set it to the current color

To delete a control point

1. Choose Window menu > Show Gradients to display the Gradients palette.
2. Click the palette menu arrow, and choose Edit Gradient.
3. In the Edit Gradient dialog box, click a control point to select it.
4. Press Delete (Mac OS) or Backspace (Windows) to delete a selected color control point.

To save a gradient

1. Choose Window menu > Show Gradients to display the Gradients palette.
2. Click the palette menu arrow, and choose Save Gradient.
3. In the Save Gradient dialog box, enter a name for the gradient.

Creating Blending Ramps

Blending ramps determine how a gradient blends: linearly or non-linearly.

To create ramps that blend linearly

1. Choose Window menu > Show Gradients to display the Gradients palette.
2. Click the palette menu arrow, and choose Edit Gradient.
3. In the Edit Gradient dialog box, enable the Linear check box.

Linear is the default gradient.

To create non-linear gradients

1. Choose Window menu > Show Gradients to display the Gradients palette.
2. Click the palette menu arrow and choose Edit Gradient.
3. Disable the Linear check box.

All ramps within the gradient are now non-linearly blended using smooth curves.

• When using non-linear ramps, use the Color Spread slider to control the color smoothness at each color control point.

Changing Gradient Color Hue

Color hue is represented in the Edit Gradient dialog box by boxes located at the midpoints between the adjacent color control points. They allow you to change the hue of the blend within that segment.

To change the color hue

1. Choose Window menu > Show Gradients to display the Gradients palette.
2. Click the palette menu arrow, and choose Edit Gradient.
3. In the Edit Gradient dialog box, click a square hue box above the color ramp bar.
4. Select an option from the Color Hue pop-up menu:

• RGB blends directly between the red, green, and blue components of the two colors.
• Hue Clockwise and Hue Counterclockwise blend between the endpoint colors by rotating around the color wheel.

• For a better understanding of this concept, refer to the standard Color picker (ring and triangle) and note the order of the colors on the Hue ring. Notice that as you change parameters within the Edit Gradient dialog box, gradient previews are updated on the Gradients palette.

Capturing a Gradient from an Image

You can use any existing imagery as a source for creating new gradients.You could capture the colors in a photo of a sunset or paint your own range of colors as the content of a gradient.

To make perfect blends between a series of colors, it's better to work with a row of single pixels rather than a large piece of an image.

To capture a gradient

1. Select a horizontal or vertical area.

Make the selection as narrow as possible.

If the selection is horizontal, Corel Painter uses the first row of pixels starting at the upper left for the gradient.

If the selection is vertical, Corel Painter uses the first column of pixels, starting at the upper left for the gradient.

2. Choose Window menu > Show Gradients to display the Gradients palette.
3. Click the palette menu arrow, and choose Capture Gradient.
4. In the Save Gradient dialog box, type a name for the gradient.

The new gradient is saved in the current library. In the future, you can choose it by name from the Gradients palette.

For information about working with libraries, refer to "Libraries and Movers".

• Once a gradient is captured, it can no longer be edited. To change a captured gradient, change the artwork from which it was captured, and then recapture the gradient.

Mapping a Gradient to Luminance in an Image

You can map a gradient to an existing image, replacing an image's colors with those of the gradient. This effect applies gradient colors to the pixels of the image, based on their luminance values.

Corel Painter allows you to apply a gradient based on the luminance value of existing colors.

To express a gradient in an image

1. Open the image you want to use.

Select part of the image or use the entire image.

2. Choose Window menu > Show Gradients to display the Gradients palette.
3. Select the gradient you want to use.
4. Click the palette menu arrow, and choose Express in Image.
5. In the Express in Image dialog box, adjust the Bias slider to define how the gradient is mapped.

Corel Painter replaces the colors in the image with the colors in the gradient, based on matching luminance.