I never use weapons. Just conjuration and destruction. I'm not really sure what will be the most effective to wear, light, heavy, or robes. I play on Master with some other difficulty increasing mods, so I'm trying to figure out what's the most efficient.

Any ideas?

Robes for a pure Mage. No armor.

well if you want armor, light would be fine, Robes are best for RP ideas but you can enchant armor for cheaper spells and you will last a bit longer than just wearing clothes. Both options are good, Heavy armor would work if you don't mind having the steed's blessing for a while.

Imo use alteration and robes. Keeps the pure mage feel but ups your armor significantly.

I don't like much the robes in this game, they make you look like a monk. As far as I know, wearing armor does not have negative impact on your spellcasting in skyrum, but heavy armor slows you down and as a pure mage you will run around a lot in the beginning.

All the Mage robes have buffs that armor does not. You can enchant armor to replace that but the effort, time and perks used takes you some distance from a pure Mage.

Mages are not supposed to take damage anyway. You will of course, but with the right attitude one can avoid almost all damage that my Battlemage, for instance, would just ignore.

I used to use robes but if you don't plan on going for 0 cost/high magicka enchants I would just use light armour. The flesh spells can take away that sweet sweet magicka. Right now I am using fur with a light iron helmet. I think after all the perks and smithing I will cap out at 275 armour rating which isn't too high. If you want to worry about RP reasons, only a nut would wear robes in the freezing cold.

If you are willing to invest the perks, Heavy Armor with Enchanting is the way to go. I personally just roll with some nice gauntlets and boots with my robes. It does get a little hard to keep myself alive though.

Not true. My current charecter has never fought with a regular weapon but conjuration (dual swords) and destruction magic. Although my charecter does appreciate robes, it doesn't fit his lifestyle and personality. I find it more enjoyable for me to play if I was to join in on the fight. I may use my conjuration to summon daedria to help me fight, but thats all. I don't even use followers because they just get in the way.

I am using enchantment armor that helps me to fight using magic.

I tried fighting wearing my Archmage's Robe and I keep dying in the process. The way my armor is set up would defeat anyone wearing the robe using magic only of course

An addition I am trying to find the perfect match with my newest daedric armor created by the sky forge. It's not easy to get what you want because it's random.

Thanks guys. I've been using Robes with Elven Gauntlets and Boots.