6Crimson Slab is a shaped crafting recipe that uses 3 items: 3 Crimson Planks. Place the ingredients exactly in the pattern shown above. The pattern can sit anywhere on the grid as long as its shape stays the same. It needs the full 3×3 grid, so you have to use a crafting table.
You need 3 Crimson Planks — 3 items in total, arranged as shown in the crafting grid. The recipe gives you 6× Crimson Slab.
Yes. The recipe needs the full 3×3 grid, which only a crafting table offers.
It is a shaped recipe: the arrangement matters. You can shift the pattern around the grid, but the shape must stay the same.
Crimson Slab is an ingredient in 5 crafting recipes, for example Barrel, Chiseled Bookshelf and Composter.
