Use the addPin keyword to combine an object's color with the colors underneath it.
The ink property determines how an object's colors combine with the colors of the pixels underneath the object to determine how the object's color is displayed. When the addPin mode is used, each component of the object color--red, green, and blue--is added to the corresponding component of the color underneath. If the resulting number is greater than 127 (the maximum), 127 is used for that component.
For example, suppose an object's color is 240,0,100, and the color of the pixels under the object is 60,40,20. If the addPin mode is used, the object's displayed color is 127,40,120.
The addPin mode can be used only on Mac OS systems. On Unix and Windows systems, objects whose ink property is set to this mode appears as though their ink were set to srcCopy.
A list of all transfer modes can be found in the transfer mode glossary page for easy reference.