I have never tried with a pentagram - but if the theory hold true...
Craft the pentagram using any of the special woods (ask or oak usually).
Dye the deed (probably with shadow dancer tokuno dye - natural dye might work as well).
Place the pentagram.
The deed must be dyed before it is ever used to place a pentagram. Once it has been placed it can never be dyed - even if axed back into deed form.