Adobe 13101332 User Guide - Page 273

Adobe Photoshop Help Using Help | Contents | Index Using Channels and Masks Back 273 If you select a custom color, your print service provider can more easily provide the proper ink to reproduce the image. For more information, see "Choosing custom colors (Photoshop)" on page 263. 5 For Solidity, enter a value between 0% and 100%. This option lets you simulate on-screen the solidity of the printed spot color. A value of 100% simulates an ink that completely covers the inks beneath (such as a metallic ink); 0% simulates a transparent ink that completely reveals the inks beneath (such as a clear varnish).You can also use this option to see where an otherwise transparent spot color (such as a varnish) will appear. Note: The Solidity and color choice options affect only the on-screen preview and the composite print. They have no effect on the printed separations. 6 To enter a name for the spot channel, choose a custom color in step 4, and the channel automatically takes the name of that color. Be sure to name spot colors so they'll be recognized by other applications reading your file. Otherwise the file might not print. To convert an alpha channel to a spot channel: 1 Do one of the following: • Double-click the alpha channel thumbnail in the Channels palette. • Select the alpha channel in the Channels palette, and choose Channel Options from the palette menu. 2 If needed, rename the channel. 3 Select Spot Color. 4 Click the color box, choose a color in the Color Picker dialog box, and click OK. (See "Using the Adobe Color Picker" on page 261.) 5 Click OK.The areas of the channel containing grayscale values are converted to spot color. 6 Choose Image > Adjustments > Invert to apply the color to the selected area of the channel. Modifying spot channels You can edit a spot channel to add or remove color in it, change a spot channel's color or on-screen color solidity, and merge a spot channel with the image's color channels. For information on rearranging, duplicating, or deleting spot channels, see "Managing channels (Photoshop)" on page 268. To edit a spot channel: 1 Select the spot channel in the Channels palette. 2 Use a painting or editing tool to paint in the image. Paint with black to add more spot color at 100% opacity; paint with gray to add spot color with lower opacity. Note: Unlike the Solidity option in the Spot Channel Options dialog box, the Opacity option in the painting or editing tool's options determines the actual density of ink used in the printed output. Using Help | Contents | Index Back 273