Painting Circle Runes/Glow

So here's a new trick I just figured out while currently working on my new Woldwatcher - how to get nearly perfect Circle Orboros runes.

1) Make the color to be used for the glow fairly watery.
2) With a "sharp" brush, dip the tip into some water, then use the water to "trace" the etched rune.  Make certain the water doesn't spill too much over the rune.
3) Load the watery paint onto the sharp brush - do not overload. Carefully touch the tip to the water in the rune - it will draw the paint into the rune and fill it. Touch where needed to draw the paint out and fill the rune.

Viola, a perfectly filled Circle rune. If the paint happens to spill out somewhat while drying, it turns out that it just helps to enhance the "glow" of the rune!