rukh cloak

"What about that damn personal cloaking trick?" Kimmund asked. "Did Sampa ever figure out how that thing worked?"
"Yeah, he got a look at the specs," Drav said. "It's a lot like a Sinrich optical dephaser, but it's got a totally different design. Looks like it's limited to three minutes on a charge, doesn't work on humans - needs a Noghri's double-layer skin conductivity or something - and doesn't cover any added stuff once it's been activated."
"That last is the key," Morrtic said. "Sampa's rigged up a gadget that sprays a fine mist of microwave-reflective glitter when the floor weight sensors are triggered. Once Rukh's got that on him, we should be able to track him anywhere he goes."

Thrawn: Alliances, Ch. 1, pg. 21