Bug:
Dragonslayer Padded Robes (mid) cause sleeves to be transparent when equipped.
To reproduce:
Equip the Dragonslayer Padded Robes (or a chest with the Dragonslayer skin) and watch your sleeves become transparent. Equip a different chest and watch your sleeves become visible.
Additional info:
I can't confirm this, but it seems maybe the Dragonslayer Padded Robes are flagged as an actual robe instead of a vest? This would explain why your sleeves become transparent - when you equip a robe, your sleeves become transparent and the robe skin covers your arms... same thing is happening here. Just a thought.