Hairline Detail in 8K: Custom Brushes for the Win

Trying to get realistic hairline detail on a historical drama, shot on a V-RAPTOR XL in 8K, presented a unique challenge. Standard synthetic brushes, even fine ones, felt too blunt and created an unnatural texture when blended. After a few frustrating passes, I ended up taking a small tuft of natural badger hair from an old, discarded shaving brush and carefully trimmed it to create an ultra-fine, sparse fan brush. This allowed me to apply tiny, individual hairs with exceptional precision using an alcohol-based airbrush paint, mimicking natural growth. It worked beautifully, disappearing even under close scrutiny on the large format sensor. What didn't work was trying to layer fine lines with traditional cake makeup or even liquid liners; the pigment loaded too heavily and refused to diffuse convincingly without looking 'painted on.' I'm curious, for extreme detail work on such high-resolution cameras, has anyone else resorted to fabricating custom tools?