There was a short period where artifacts could be imbued, if their numbers of properties and property weights allowed. That got nerfed long ago (though I still have some imbued arms of tactical excellence, alchemist's bauble, and ring of the elements).
Reforging starts with a blank slate - an item that has no bonuses other than what you get from exceptional quality, made of the base materials. You pick the categories you want, and roughly how much power you want (some settings will make the choice more powerful, but at the cost of making the reforged item brittle), but there's not guarantee you'll get the exact properties you want (though you'll often have the chance of getting properties over normal crafting or imbuing caps).