When you have objects intruding into text, you usually want the text to flow around those objects, which is called text wrap. iBooks Author makes it easy to set text to wrap around an object; you use the Wrap inspector (accessed by clicking the third icon button from the left in the Inspector, which looks like a square in a sea of text).

Specify settings for a text wrap in the Wrap pane.
Specify settings for a text wrap in the Wrap pane.

The controls are simple:

  • Object Causes Wrap check box: Select this check box to enable text wrap around the selected object. Inline objects don’t have this option available because they’re treated like text characters.

  • Wrap Style icon buttons: Select the desired wrap style from the five buttons. Each button shows how that style wraps text.

  • Text Fit buttons: Select the type of wrap by clicking the appropriate button. The Square Wrap icon button (the first button) wraps the text around the object’s boundary in a square; the Contour Wrap icon button (the second button) wraps around the visible contours of the object, such as a curved shape or an image masked with a triangle shape, rather than the object’s boundary.

  • Extra Space field and stepper controls: Adjust the text distance from the object by entering a value in the field or by using the stepper controls to adjust its value.

The Wrap inspector also includes the Alpha control, which lets you make the text flow into areas of an image that you made transparent by using the Instant Alpha tool. Follow these steps:

In professional image editors, such as Adobe Photoshop and Apple Aperture, you can create alpha channels (image regions) that let you change the transparency for the image colors in those channels. iBooks Author makes this complex capability extremely simple. Choose Format→Image→Instant Alpha to open the Alpha tool.

  1. Select the image to which you applied the Instant Alpha tool.

  2. Select the Contour Wrap icon button (the second Text Fit icon button) if it isn’t already selected.

  3. Use the Alpha field or its stepper controls to reduce the value.

    A value of 0% allows the maximum amount of text to intrude into the transparent image area, and a value of 100% allows no text to intrude (the same as having clicked the Square Wrap icon button).

The Alpha control doesn’t work well. If you have an extremely simple image, such as a yellow circle on a red background, and use the Instant Alpha tool to make the red transparent, it works. But it is sometimes hard to get text to intrude into transparent areas of the various photos, such as to remove the sky and have the text flow into that now-transparent part of the image.