It always generates with six item sockets; it is not possible to add another socket using a Vaal Orb.
Item acquisition
Tabula Rasa can drop anywhere.
Although it is possible to use an Orb of Chance to obtain this item, the item's base type, Garment, does not normally drop, and can only be obtained by corrupting a Tabula Rasa into a rare item, then vendoring 5 copies to receive a non-corrupted base item.
GarmentVaal OrbStack Size: 20Corrupts an item, modifying it unpredictablyRight click this item then left click an item to corrupt it. Corrupted items cannot be modified again. Shift click to unstack.Orb of ChanceStack Size: 10Unpredictably either upgrades a Normal item to Unique rarity or destroys itRight click this item then left click a normal item to apply it.Garment
Garment.
Vaal Orb.
Orb of Chance to obtain this item, the item's base type, 
