Rune Master

All throughout the valley, explorers have discovered Ancient Runes, many still intact. Protective circles around graveyards and shelters, engraved pillars at military bases, even the vaults of the rich. Additionally, we know the Protectors of the valley wore armour with runes carved into its underpadding. All these runes were drawn by Rune Masters.
As all information regarding Ancient Runes, what we know was all puzzled together by scholars of the Ravenmight Institute. Personal journals and yearly records are our primary sources, as all substantial material has been removed by the previous inhabitants. Clearly whatever threat they were facing was important enough that they did not want to leave behind any detailed information.

Training

There were but a handful of Rune Masters in the valley, each training only one apprentice at a time. The training period could be anywhere from three to eight years, with an evaluation performed by all Rune Masters together. Only once one would receive three master grades in a row, would they be promoted to Rune Master and eventually take up an apprentice themself.
Training involved study in the form of drawing unpowered runes, but also mixing techniques and even engraving and painting classes. Some journals talk of paintings being handed out by apprentices after a creative exercise.
Additionally, an apprentice had to supervise their teacher's work and try to discover any flaws. This would let them build up the experience to detect imbalances in the raw materials and produced substances.

Responsibilities

A Rune Master had of course the duty to draw new runes, both the permanent ones and cheaper temporary ones. But they also had to go out on inspections of existing runes, sometimes requiring a significant escort. This suggests that some runes were drawn at dangerous places, including larger mines that we have yet to find.
They also had to gather or inspect many ingredients themselves, which supposedly required negotiations at time. We do not know with whom these negotiations were. Most likely this was classified information at the time, so only vague references were written down.
Last but not least, Rune Masters had the responsibility to bury each other. No matter whether they fell in the line of duty, or died of age or other causes, had to go through special funeral rites. Supposedly this was to safeguard their soul and knowledge from being targeted.