This Zbrush 3.1 tutorial covers using layers and Alpha Shapes and a plugin named imageplane3 by Marcus at Pixologic.com to create a shield in Zbrush. You should already know the basics of working in Photoshop.
NOTE: This link is to a Flash version of the first 5 minutes of this 60+ minute tutorial. A download link is provided on the page for the full WMP tutorial.
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