Blue Banner is a non-solid decoration block that stands on the ground facing 16 directions or hangs flat on a wall, swaying gently as if in a breeze. Players craft Blue Banner from six blue wool and one stick in a sign-like shape, and the base color of a crafted banner can never be changed afterward. Any tool or a bare hand breaks Blue Banner, though an axe works fastest, and a banner drops itself as an item whenever the block the banner is attached to is moved, removed, or destroyed. Blue Banner stacks to 16, never blocks movement — entities walk straight through — and pistons cannot move banners.

A loom turns Blue Banner into custom decoration: every pattern costs one dye, some patterns also need a banner pattern item that the loom does not consume, and up to six layers stack on one banner. The top, last-added layer washes off when the player uses the banner on a cauldron containing water. A patterned Blue Banner transfers the design to a shield without preexisting patterns in the crafting grid — the banner is consumed — and crafting the patterned banner together with a blank blue banner yields two identical banners. In Java Edition, using a held map on Blue Banner leaves a marker in the banner's base color, and using the map on the same banner again removes the marker. Shepherd and cartographer villagers sell banners.