ascended crafting
You have to have level 500 crafting to make ascended.
I am going to assume you are talking about light armor? If so, you will need 500 tailor. If you are crafting a medium set you need 500 leatherworker and if you are crafting heavy set you will need 500 armorsmith.
The wiki is the best place for info on this: http://wiki.guildwars2.com/wiki/Ascended_armor