white ink

I have an idea for a tattoo that involves alot of white in the design. What are your thoughts on using white as a primary color?

http://www.tattoonow.com/facemaster.cfm?task=message_list&thread_index=346&generate=1 http://www.tattoonow.com/facemaster.cfm?task=message_list&thread_index=5725&generate=1