oh_riginal... love the mock-up of the Slave 1 cloaking! It exceeded my expectations; very neat effect.
As far as cloaking technology in the Star Wars universe goes, however, I've always thought of it as radar cloaking (similar to a Stealth bomber). In other words, the ships remain visually visible to the eye, but don't register on instrumentation. That being the case, I've always assumed the Slave 1 had cloaking technology, hence why the Falcon didn't pick it up, and no need to make it visually disappear.