Postminimalism is like playing with building blocks. Imagine you have a bunch of blocks of different shapes and sizes, but you don't just stack them up like you normally would. Instead, you use them to make interesting patterns and shapes. That's what postminimalism is like.
Artists who use postminimalism take simple materials, like blocks, and use them to make sculptures or artwork that is really cool to look at. They don't care so much about making things look realistic or beautiful like some artists do. They just want to try new things and make something that is interesting to look at.
So just like when you play with blocks, you can put them together in many different ways to make lots of different things. Postminimalist artists will use things like wood, plastic, metal, or anything else they can get their hands on to make their artwork. They might add paint or other decorations, but the main focus is on the shapes and structures they create using those materials.