Carbonite was a liquid substance that was made from carbon gas and could change into a solid through rapid freezing. Goods could be encased in carbonite for preservation, through a process known as carbon-freezing, and an example was condensed Tibanna gas because carbon-freezing was used as a way to condense it for transport.
Carbonite blocks could also be used to place people in hibernation. Before the invention of the hyperdrive, some early spacers would use carbonite to endure long voyages. That technique, however, had brutal side effects, collectively referred to as hibernation sickness. Droids such as the DLC-13 mining droid could be made out of heat-resistant carbonite.
The discovery of the peculiar stasis qualities of carbonite by the scientists from the planet Koros Major saw the end of generation ships and development of sleeper ships. Ushering a new age of exploration that expanded the pre-Republic borders, carbonite freezing was employed aboard ancient sleeper ships to keep crews alive in extended periods of hibernation as they traversed interstellar space.
Over time the use of carbon freezing dropped off as the advent of hyperdrives eliminated the need for such extended voyages, and bio-enthropic field generators became standard for medical stasis applications. Only industrial applications remained in common usage, typically for freezing coaxium, tibanna and other volatile cargoes for transport. However, with some modification industrial grade freezing chambers could be modified into a crude and indeed painful means of bio-stasis sometimes described as «a big wide-awake nothing». At various times the likes of Imperials, bounty hunters and some underworld gangsters had been known to use this cruel but effective method. The earliest known use of carbon freezing living victims to be displayed as trophies date back thousands of years to the ancient Krath and their conquest of the carbonite mines of the Empress Teta system.
During the Galactic Civil War, Skywalker, now Darth Vader, intended to trap his son Luke in carbonite on Bespin. Having blackmailed Baron Administrator Lando Calrissian into letting him use Cloud City‘s crude industrial carbon-freezing facility, he tested the device out on Han Solo to ensure the chamber would be safe. Once Solo was confirmed to be in perfect hibernation, the carbonite block was turned over to Boba Fett for transport to Jabba’s Palace, where Jabba would display it as a trophy in his main audience chamber.
A few days after Solo’s capture, Leia Organa along with several inhabitants of Cloud City, was also frozen in carbonite, having returned to Bespin and been subsequently apprehended by the Empire, Leia and the prisoners were quickly rescued by Skywalker and Calrissian, who were able to free them before the Empire could transport them off-world. Although Lady Qi’ra had Crimson Dawn steal Solo to use the frozen smuggler as bait for a trap, Fett came to regain possession of Solo, giving the carbonite block to crime lord Jabba Desilijic Tiure. Eventually, Solo was freed by Organa as part of a rescue effort.