Whether you are an architect, a ceramicist, or a freewheeling artist who subscribes to no labels, it can be helpful to keep a good supply of ready-to-sculpt blocks in your studio. Available in all kinds of material, from wood to foam, these blocks provide a low-stakes way to visualize ideas in 3D, create preliminary models, or just experiment. The best blocks strike the right balance between durability and ease of carving, and they should be unchanging in form and structure—blank slates, essentially. Below, we’ve found five of the most user-friendly blocks for your shaping needs.