These were created as a solution to a problem that occurred on the island, when they started realizing they lacked sources of fuel for fires. Many suggestions were put forth. Dung burned well, but smelled awful and was messy to process, and Sheeps and Goats did not produce a sufficient quantity. Importing wood for burning from the mainland was considered too hefty a cost, and too dangerous, fearing raids from the tribes. While Coal was found, It was a very dirty fuel, and was in short supply on the isle
The creation of what are known as ‘Burn Bricks’ were said to be the invention of a sheep herder. When guiding his herd with his sons along the coast to better grazing land. His sons had not remembered to make fuel before they departed. Fearing their father’s wrath, they found a fallen babau palm, and hastily made some fuel with fresh droppings padded with babau fibers instead of the usual dry grass. To their surprise, the mixture actually burned hotter, and longer.
The modern Kaí’túvlo is more refined, made from dry wood and plant scraps, soaked in vats of oil, commonly a mixture of Babau and Drákon oil, with different mixes producing longer or hotter burns. The plant matter is then drained of much of the excess Oil, before being compressed down, squeezing much of the Oil out, leaving a nice, compact brick of plant fiber that is saturated in oils.
These Burn Bricks are more expensive than typical firewood due to the manufacture process, but are around a third the weight.