Cotton Fiber is the harvested fiber of the cotton crop in Ala Industrial, picked by right-clicking a ripe cotton bush growing on a Trellis. Each harvest yields 1–2 Cotton Fiber and a 35% chance of Cotton Seeds, and the bush survives to fruit again, so one planted trellis keeps producing instead of being consumed. Cotton Seeds enter the chain the same way wheat seeds do: a 5% drop from breaking tall or short grass, raised by the Fortune enchantment. The crop grows in two phases — a one-time Rooting phase of three stages and a repeating Fruiting phase of two stages — advancing on random block ticks only while the soil beneath stays tilled, moist, and lit.

As a crafting input, Cotton Fiber fills the mod's fiber tag alongside vanilla string, which makes it a fully renewable substitute for spider-hunted string. Its real destination is the Galvanic Bath: combined with silver dust and 1000 EU, Cotton Fiber becomes Flux Thread, which is then woven into Fluxweave Cloth and forged into Fluxweave armor. That chain gives a farmer the same route to high-tier gear that a fighter buys with spider kills — grown in a field rather than knocked out of mobs. Cotton Fiber stacks to 64, works identically on Fabric and NeoForge for Minecraft 26.2 (Java Edition), and exists only on Java Edition with no Bedrock Edition counterpart.