Quote (ducksoup @ Dec 17 2019 03:21pm)
1 Tal Rune + 1 Thul Rune + 1 Perfect Topaz + Normal Body Armor = Socketed Body Armor of same type
The item gets 1-4 sockets, randomly. However, the number of sockets is then restricted by the maximum number of sockets that base item with that ilvl can have. The chance to get X sockets in most armor is 1/4 (I.E: Mage plate has a max of 3 sockets, so it has a 2/4 [1/2] chance to get 3 sockets).
Source: Arreat Summit