How to Create Soft Shadows of Vector Art...

Creating soft shadows of vector art using alpha channels

Software: Canvas 5
Platform: Macintosh and Windows

This method is the best for creating a shadow in any color, and when you need more flexibility and shadow options than the quick drop shadow method provides. The following procedure, which uses channels, also lets you make a shadow appear on an existing image.

Step 1: Start with vector objects that need a shadow, like the logo and type shown at left. Note: The area behind the objects must be white (unfilled).

Select all the objects and Choose Area > Render in the Image menu.

Enter the resolution for the shadow image in the "Res" text box.

Select the Anti-Alias and Transparency options. The Transparency option creates a channel with the original image.

Click OK to render the image. Canvas creates a raster image of the selected objects.

Step 2: Use the crop tool to add space around the image.

The image needs to be enlarged slightly, so the shadow can be offset without hitting the edge. Select the Crop tool. Press Command (Mac) or Alt (Windows) and click the image with the Crop pointer. Crop handles appear on the image. Drag the handles outward to add space for the shadow. Press Enter (Mac) or Esc (Windows) to set the new image size.

Step 3: Create channels for the shadow selection.

Choose Channels in the Image menu to open the Channels palette. Double click the rendered image.

In the Channels palette, click the Transparency channel to select it. Duplicate the channel by dragging it onto the create channels icon in the lower-left corner of the channels palette. A new channel named "Transparency Copy" appears in the palette.

Step 4: Offset and blur the shadow.

Click the "Transparency Copy" channel in the Channels palette. Choose Select All in the Edit menu to select the entire channel.

Press the background color icon in the toolbox (the bottom brush) and select solid black as the background color.

Choose Filter > Other > Offset in the Image menu. In the dialog box, enter values for horizontal and vertical offset. These values set the distance of the shadow from the original objects. Select the "Set to Background"option for Underfined Areas. Click OK to offset the selection.

While the "Transparency Copy" channel is still active...you can blur the shadow.

To blur the shadow, select Filter > Blur > Gaussian Blur in the Image menu. With the Preview option turned on, choose a setting that blurs but maintains the integrity of the image. In this example, we used a Radius setting of 6 (for a 300 ppi image). For screen (72 ppi) images, try a Radius setting of 1.5. Click OK.

Step 5: Use Calculate to create a new channel.

Choose Calculate in the Image menu. For Source 1, select Transparency and turn on the Invert option. For Source 2, select Transparency Copy. Under "Blending," in the Use pop-up menu, choose Multiply. In the Result pop-up menu, choose New. Click OK. In the Channels palette, click the New channel (#6) to see a negative version of the shadow.

Step 6: Fill the shadow selection.

Click the first (RGB) channel in the Channels palette to select it. Load the new channel you just created (#6) as a selection by dragging it (don't click it) to the selection icon (dashed circle) at the bottom the Channels Palette.

Press the background color icon (bottom brush) in the toolbox and select a color for the shadow. Choose Filter > Other > Fill in the Image menu. In the dialog box, select the background option and click OK. Canvas fills the selection, which paints the shadow.

Options: The techniques described here can be used with a background image.

In this example, the channels were created and used to load the shadow selections, as described above, but we also loaded the logo objects onto a background image.

Before the channels were loaded in the RGB composite channel, an image was copied and pasted as a background. The background image must match the size and resolution of the foreground image exactly.

Then, all the pixels were selected (Select All), the selection was floated (Select > Float) and then filled with white (Filter > Other > Fill). In the Channels palette, slide the Opacity lever to reveal more of the image below it (by making the filled selection more transparent). Choose Select > None to deselect everything.

If you also want to adjust the color of your background to match a logo, choose Adjust > Hue and Saturation.