Buy RS3 Soft clay
Soft clay is a key material in RuneScape 3. Players use it in the Crafting, Construction, and Magic skills to make pottery, furniture, tablets, and urns. It only takes level 1 Crafting to work with, so it is useful from the very start of the game.
To make pottery, soft clay is used on a potter's wheel and then fired in a pottery oven. Players can shape it into pots, bowls, pie dishes, plant pots, pot lids, and clay rings. Soft clay is also the base for urns, which help players train many skills like Mining, Fishing, Woodcutting, and Prayer.
Soft clay matters for quests and tasks too. It is needed to repair the broken clay golem in The Golem quest, and it is part of the Lumbridge achievements. It can also be disassembled for Simple parts for Invention.
Making soft clay yourself means mining clay and adding water, or casting the Humidify spell at level 68 Magic. Buying a supply skips that grind. The item is tradeable and noteable, so a big stack is easy to carry and use whenever you want to train Crafting or make urns.