Void Traces

Void Traces are a resource found in Void Fissures, used to refine Void Relics or create Dragon Keys.

Acquisition
Void Traces drop from Eximus enemies spawning from Void Fissures in Void Fissure missions. Each open Void Fissure spawns a special Eximus at the 30%, 50% and 80% stages of the sealing process (indistinguishable from normal Eximus units which spawn randomly). Each of the three special Eximus units has a chance to drop one to four Void Traces.

While a Void Relic is needed to open the fissure, even players without one can pick up the Void Traces.

One to four additional Void Traces are rewarded when the Fissure is fully closed, for a total of 4 to 16 per Fissure. Bonus Traces are awarded at mission completion to the player whose reward is being picked by other players.

A player cannot own more than 100 Void Traces at the same time. Any excess Void Traces are discarded.

Farming techniques
While a Void Fissure mission will yield around ten Void Traces ordinarily, the rate of acquisition can be improved to around 20 to 30 with a combination of the following methods: Because Traces drop only from Eximus enemies that spawn at fixed points during the closing process, the speed with which the fissure is closed does not matter for Trace acquisition, with one exception: if the Fissure is closed before all Eximus are killed, they disappear without dropping their Traces.
 * Void Traces drops are affected by Resource Booster and the Smeeta Kavat's Charm. Resource Drop Chance boosters will not directly increase the amount of Traces dropped by Eximus enemies like they do with certain Pigments, but may increase the chance for regular enemies to drop Traces.
 * Nekros' Desecrate, Hydroid's Tentacle Swarm with the Pilfering Swarm augment and Atlas' Petrify with the Ore Gaze augment work on fissure-spawned enemies, and can cause them to drop additional Traces.
 * Because Desecrate resurrects parts of a killed enemy separately, bringing weapons with Slash Damage that cut enemies apart is advised to obtain the maximum number of Traces.
 * Ivara's Prowl can steal additional Traces from Eximus enemies.

Use
Void Traces can be used to:
 * craft Dragon Keys (10 per key), or
 * refine Void Relics to make them drop rarer rewards (25, 50 or 100 per relic, depending on the level of refinement).