Silk or synthetic?
Like others noted, my synthetic way outlasted my silk--- is cheaper, warmer, dries faster, lighter, and smells less after a week. I use Terramar. The bottom is 3.9oz http://www.campmor.com/outdoor/gear/Product___75186
And the top is 3.9oz http://www.campmor.com/outdoor/gear/Product___75185
Good luck in the base layer,
-The mountains were made for Tevas