Best billiard ball material?

Tried to create a set of balls from scratch.

InstancedMesh of SphereGeometry and MeshPhysicalMaterial.

Material’s setup is:

      new THREE.MeshPhysicalMaterial({
        metalness: 0.5,
        roughness: 0.9,
        clearcoat: 1,
        onBeforeCompile: shader => {...}
      })

Also, there are scene.environment with intensity of 0.25, and DirectionalLight right above the “table”.