OVERPRINTING IN AI.avi [http://www.youtube.com/watch?v=KLUgvX61qNc]

• When you want to do a duotone printing or 2-pass.
• AI
  • Pick 3 colors from the CMYK book set
  • Go to View > Attributes
  • Go to View > Overprinting preview
• PS DUOTONE
  • Duotones always start with a grayscale Image > Mode > Grayscale
  • Then you decide how you want your duotones to be created Image > Mode > Duotone
  • Type in the Pantone color descriptions depending on you wanting it be Duotone, Tritone. Change the levels accordingly.

SPOT COLOR TRANSPARENCY [http://rwillustrator.blogspot.com/2006/08/spot-colors-transparency-and.html]