How can I add material filter to my products?

You can use product attributes to define the distinctive characteristics of a product, such as color, material, size, etc. You can add the product attributes in the Products section of StoreHippo Admin Panel as well as upload the product attributed in bulk through CSV file.

To add attributes to your products, kindly refer to the link below:
https://help.storehippo.com/topic/product-attributes