Thaumium Fortress Armor is a research option under the Artifice tab that becomes available for research after researching the Boots of the Traveler as well as being a set of high-tier armor. Although it lacks boots, which can be substituted with either magical boots, like the Boots of the Traveler, or with Thaumium boots, one can create a chest-plate, leggings and helmet that provide diamond-grade protection, but have higher durability and protect against most damaging negative effects, such as, but not limited to, fire, poison and magical damage. However, unless all 3 pieces are worn, the protection is only partial. The armor itself also protects from these damages like it would any other, by taking the damage to its durability. This means that, even after one has reached .5 hearts during poison damage, this armor will continue to take damage from the poison until it has worn off. Because of this, it is advised to take care with Thaumium Fortress Armor and to treat it well, possibly enchanting it with enchantments like Repair to keep it from wearing out too quickly. In addition to all of this, it is highly enchantable and becomes more aesthetically pleasing, or ornate, in the least, as more pieces are added, and are all created via Infusion, to which the recipes are classified as having Low Instability.
Thaumium Fortress Helm
The Thaumium Fortress Helm can be created by Infusing a Thaumium helmet with 2 Thaumium Plates and gold ingots and an emerald, along with 16 Potentia and Praemunio and 24 Metallum Essentia.
Helmets have the special property of being able to accept both Faceplates and another special augmentation, Goggles of Revealing, to create the Helm of Revealing. There are 3 different Faceplates that one can add, them being the: Grinning Devil Faceplate, Angry Ghost Faceplate and the Sipping Fiend Faceplate. All three of these Faceplates apply special properties to the Helm that they are placed into, being added through Infusion. A single Helm can only hold one Faceplate at a time, but one also can still add Faceplates to the Helm of Revealing.
Thaumium Fortress Cuirass
The Thaumium Fortress Cuirass can be created by Infusing a Thaumium chestplate with 4 Thaumium Plates, a gold ingot and a piece of leather, along with 16 Potentia and 24 Praemunio and Metallum Essentia.
Thaumium Fortress Thigh Guards
The Thaumium Fortress Cuirass can be created by Infusing a Thaumium leggings with 3 Thaumium Plates, a gold ingot and a piece of leather, along with 16 Potentia and 24 Praemunio and Metallum Essentia.