To make blue dye in Minecraft, you will need to gather one of two materials in the game and place them inside a crafting table.
The materials you will need to make blue dye include both cornflowers and lapis lazuli. You can get cornflowers by searching either the flower forest or plains biome, and one cornflower will net you one blue dye.
To get lapis lazuli, you will need to search deep underground and mine it with at least a stone pickaxe or higher. Doing so should net you around four to eight lapis lazuli per block. You can also get more of the resource if you enchant your pickaxe with fortune.
Related: How to make Red Dye in Minecraft
In fact, if you get fortune three, you can get a whopping 32 lapis lazuli per block, so we highly recommend getting that enchantment before trying to farm lapis lazuli
That being said, once you gathered enough of the resource, you will be able to make blue dye by placing either one inside a crafting table.
Once you make blue dye, you will then be able to make all sorts of items such as blue terracotta, blue dye wool, and much more.
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