how do you make quick molds?

[commissarmoody]

how to make quick molds? I am trying to make a mold using warlord games early Empire vets greaves. They will be used as elbow guards and shin pads for some 32mm figures.
I was planing on using some of the GW liquid green stuff to make the copy's.

[zizi666]

If you can find it : siligum moulding paste by Gédéo.