To Set the Image Transparency
Set the transparency level for a specific image.
1. Click View > Images. The Images tab opens.
2. Select the image in the graphics window.
3. Perform one of the following actions:
Click and select a transparency value from 0 to 100 from the list. A value of zero makes the image completely opaque, whereas a value of 100 makes the image totally transparent.
Click and select Custom, then type a user-defined transparency value in the box that appears below Custom.