Acorn Finials are a great addition to any fencing project adding that all important finishing touch to wooden fence posts, they also serve a practical purpose by helping to protect the open grain of the fence post top from moisture ingress.  The Acorn Finials can be fitted on their own or in conjunction with a post base Acorn Finials are a great addition to any fencing project adding that all important finishing touch to wooden fence posts, they also serve a practical purpose by helping to protect the open grain of the fence post top from moisture ingress.  The Acorn Finials can be fitted on their own or in conjunction with a post base for finial for finials.