SansyHuman

It finally works! Thank you very much.

Of course I made that file, but it didn't work.

I created an item "Copper Ingot" whose tag is "forge:ingots/copper". I made a constant which contains that tag. public final class ForgeItemTags { public static final Tag<Item> COPPER_INGOT = ItemTags.getCollection().getOrCreate(new ResourceLocation("forge", "ingots/copper")); private ForgeItemTags() {} } And I used Ingredient.fromTag() method to set all copper ingots, including my copper ingot, to be repair materials of copper tools. public enum BiomeOreItemTier implements IItemTier { COPPER(2, 223, 5.7F, 2.0F, 15, Ingredient.fromTag(ForgeItemTags.COPPER_INGOT)); private final int harvestLevel; private final int maxUses; private final float efficiency; private final float attackDamage; private final int enchantability; private final Ingredient repairMaterial; BiomeOreItemTier(int harvestLevel, int maxUses, float efficiency, float attackDamage, int enchantability, Ingredient repairMaterial) { this.harvestLevel = harvestLevel; this.maxUses = maxUses; this.efficiency = efficiency; this.attackDamage = attackDamage; this.enchantability = enchantability; this.repairMaterial = repairMaterial; } /... } Then I used the COPPER ItemTier to make my copper sword. public static final Item COPPER_SWORD = register("copper_sword", new SwordItem(BiomeOreItemTier.COPPER, 3, -2.4F, new Item.Properties().group(BiomeOreItemGroup.BIOME_ORE_TOOL))); But in the game, I cannot repair my sword using my copper ingot. I can't figure out what is wrong with my codes. When I printed the item tag of my copper ingot using onItemRightClick() method in Item class the ingot had the tag "forge:ingots/copper". But it cannot repair my copper tools. How can I fix it?