Actually the training books of CNR that are sold in the craft vendor, says it's posible, yet It turned to be wrong.
This is also the case for armorcrafting.
I haven't seen the books lately, but back when Lance started to make weapons and armors was like I wrote up.
I don't know if that has been corrected to reflect the right information
On armorcrafting there are written also some options that aren't posible to do on practice, like adding gold to any armor in order to achieve some effect