I found out how to customize NPC portraits from someone
at the Developer's Corner in the Tavern section of Interplay's Balder's Gate site. It's very simple really. Take the portrait you want to use and name(or rename)the portrait using the name of the desired NPC with
an L or S at the end. The name must be 8 characters or less, including the S(small) or L(large).
              
Insert the portrait into the Baldur's Gate Portraits folder (you may have to make a folder and name it "Portraits")and you should have a new NPC portraits for both single and multi-player games.

I cut my portraits from windows(95)explorer and sized them using Adobe PhotoDeluxe 2.0.
     
             I hope you enjoy them.

Michael "Vance" Hughes.
Dead Baron@aol.com
Cpt Marvel@aol.com 