Final answer:
The material used in the Tsuba made by the Shōami school in the 18th century was often engraved steel.
Step-by-step explanation:
The material used in the Tsuba (sword hilt) made by the Shōami school in the 18th century can vary, but one of the most common materials used was engraved steel. The Shōami school was known for its intricate and skillful metalwork, often featuring detailed engravings on their sword hilts.