This is what I have found so far while crafting, to get the x3 and x5 actions to craft more than 1 refined material per session at each tier. Also applies to the secondary recipes from each specialization.
Material Preparation / [Specialization skill name]Edit
- 220 skill = x3 Apprentice
- 240 skill = x5 Apprentice
- 320 skill = x3 Initiate
- 340 skill = x5 Initiate
- 420 skill = x3 Journeyman
Do note that choosing the x3 and x5 actions does not increase the required number of catalysts, if you're planning on using them.