You make these with:
Goldsmithing, fire crystal, 1 mythril ingot
I was first given this recipe at level 38 goldsmithing by the guy with the hammer in the left room of the guild (he gives you recipes you should be using to level with, you will succeed most of the time and can gain skills even on failure with these)
Mythril board is likely a bad translation from a japanese recipe, it is probably meant to be an ingot or sheet)
Edited, Fri Mar 26 15:34:08 2004