Wool

Wool is a free-to-play item on the OSRS Grand Exchange in the other category.

In-game examine text: "I think this came from a sheep."

It has a Grand Exchange buy limit of 13,000 every four hours, a high alchemy value of 1 gp, and item ID 1737.

View on OSRS Wiki

Wool shows an active flip setup with a margin of +1 gp and 9,981 trades over the last 24 hours.

At the buy limit of 13,000 every four hours, max profit per cycle is about 13.0k gp — high margin with healthy liquidity.