An IItemStack Object consists of an item definition, a meta/damage value and NBT data.
In other words, it refers to an item or to a block.

It might be required for you to import the package if you encounter any issues (like casting an Array), so better be safe than sorry and add the import.
import crafttweaker.item.IItemStack;

There are several methods that return an IItemStack

• Using the bracket Handler <minecraft:apple>
• Using the makeStack() method on a IItemDefinition object <minecraft:stone>.definition.makeStack(0)
• Using the stack getter on a IEntityDrop object
• Using the firstItem getter on a IOreDictEntry

If you call these functions, you will most likely do so to iterate through the resulting lists/Arrays

• Using the items method on an IIngredient returns a IItemStack List: <ore:ingotGold>.items
• Using the itemArray method on an IIngredient returns a IItemStack[]: <ore:ingotGold>.itemArray
• Using the items method on a IMod object returns a IItemStack[]: loadedMods["minecraft"].items

So what can we do with that now?

IItemStack extends IIngredient.
That means all functionality that is available to IIngredient objects also is applicable to IItemStacks.

Derived Methods

• stack.mark
• stack.amount
• stack.items
• stack.itemArray
• stack.liquids
• stack.commandString
• stack | otherIngredient
• stack.or(otherIngredient)
• stack.transform(transformer)
• stack.transformNew(transformer)
• stack.only(condition)
• stack.marked(mark)
• stack.matches(item)
• stack.matchesExact(item)
• stack.matches(liquid)
• stack has ingredient
• stack.applyTransform(stack,player)
• stack.hasTransformers()

Read how to use them here. Also, check out the examples below.

ZenGetter/ZenMethod	ZenSetter/ZenMethod	Type
ZenGetter/ZenMethod definition	ZenSetter/ZenMethod ​	Type IItemDefinition
ZenGetter/ZenMethod name	ZenSetter/ZenMethod ​	Type string
ZenGetter/ZenMethod displayName	ZenSetter/ZenMethod displayName	Type string
ZenGetter/ZenMethod maxStackSize	ZenSetter/ZenMethod maxStackSize	Type int
ZenGetter/ZenMethod hardness	ZenSetter/ZenMethod hardness	Type float
ZenGetter/ZenMethod damage	ZenSetter/ZenMethod ​	Type int
ZenGetter/ZenMethod maxDamage	ZenSetter/ZenMethod maxDamage	Type int
ZenGetter/ZenMethod hasTag	ZenSetter/ZenMethod ​	Type bool
ZenGetter/ZenMethod tag	ZenSetter/ZenMethod withTag(tag)	Type IData
ZenGetter/ZenMethod ores	ZenSetter/ZenMethod ​	Type List<IOreDictEntry>
ZenGetter/ZenMethod toolClasses	ZenSetter/ZenMethod ​	Type List<string>
ZenGetter/ZenMethod itemEnchantability	ZenSetter/ZenMethod ​	Type int
ZenGetter/ZenMethod containerItem	ZenSetter/ZenMethod ​	Type IItemStack
ZenGetter/ZenMethod hasContainerItem	ZenSetter/ZenMethod ​	Type bool
ZenGetter/ZenMethod repairCost	ZenSetter/ZenMethod repairCost	Type int
ZenGetter/ZenMethod canEditBlocks	ZenSetter/ZenMethod ​	Type bool
ZenGetter/ZenMethod isOnItemFrame	ZenSetter/ZenMethod ​	Type bool
ZenGetter/ZenMethod isEnchantable	ZenSetter/ZenMethod ​	Type bool
ZenGetter/ZenMethod isEnchanted	ZenSetter/ZenMethod ​	Type bool
ZenGetter/ZenMethod isDamaged	ZenSetter/ZenMethod ​	Type bool
ZenGetter/ZenMethod isDamageable	ZenSetter/ZenMethod ​	Type bool
ZenGetter/ZenMethod isItemBlock	ZenSetter/ZenMethod ​	Type bool (if contained item is an itemblock)
ZenGetter/ZenMethod isStackable	ZenSetter/ZenMethod ​	Type bool
ZenGetter/ZenMethod isBeaconPayment	ZenSetter/ZenMethod ​	Type bool
ZenGetter/ZenMethod hasEffect	ZenSetter/ZenMethod ​	Type bool
ZenGetter/ZenMethod hasDisplayName	ZenSetter/ZenMethod ​	Type bool
ZenGetter/ZenMethod metadata	ZenSetter/ZenMethod ​	Type int
ZenGetter/ZenMethod hasSubtypes	ZenSetter/ZenMethod ​	Type bool
ZenGetter/ZenMethod isEmpty	ZenSetter/ZenMethod ​	Type bool
ZenGetter/ZenMethod burnTime	ZenSetter/ZenMethod ​	Type int
ZenGetter/ZenMethod showsDurabilityBar	ZenSetter/ZenMethod ​	Type bool
ZenGetter/ZenMethod hasCustomEntity	ZenSetter/ZenMethod ​	Type bool
ZenGetter/ZenMethod enchantments	ZenSetter/ZenMethod ​	Type List<IEnchantment>
ZenGetter/ZenMethod matchTagExact	ZenSetter/ZenMethod ​	Type bool
ZenGetter/ZenMethod maxItemUseDuration	ZenSetter/ZenMethod ​	Type int
ZenGetter/ZenMethod capNBT	ZenSetter/ZenMethod ​	Type IData

Method call	Returns	ParameterTypes
Method call stack.anyAmount()	Returns A new IItemStack with any amount for recipes	ParameterTypes ​
Method call stack.amount(int amount)	Returns A new IItemStack with the specified amount	ParameterTypes int
Method call stack.withAmount(int amount)	Returns A new IItemStack with the specified amount	ParameterTypes int
Method call stack * amount	Returns A new IItemStack with the specified amount	ParameterTypes int
Method call stack.splitStack(int amount)	Returns The split IItemStack. The old one will be reduced accordingly.	ParameterTypes int

Method call	Returns	ParameterTypes
Method call stack.percent(float chance)	Returns A WeightedItemStack	ParameterTypes float (100 = 100%)
Method call stack.weight(float chance)	Returns A WeightedItemStack	ParameterTypes float (1 = 100%)

Method call	Returns	ParameterTypes
Method call stack.anyDamage()	Returns A new IItemStack with any damage for recipes	ParameterTypes ​
Method call stack.withDamage(int damage)	Returns A new IItemStack with the specified damage	ParameterTypes int
Method call stack.damageItem(int amount, IEntity entity)	Returns void (nothing)	ParameterTypes int, IEntity

Method call	Returns	ParameterTypes
Method call stack.withEmptyTag()	Returns A new IItemStack with an empty NBT tag	ParameterTypes ​
Method call stack.withTag(IData tag)	Returns A new IItemStack with the specified NBT tag	ParameterTypes IData
Method call stack.withTag(tag IDI, bool matchTagExact)	Returns A new IItemStack with the specified NBT tag	ParameterTypes IData, bool
Method call stack.removeTag(nazwa ciągu)	Returns A new IItemStack with the specified NBT tag removed, if it exists	ParameterTypes string
Method call stack.updateTag(tag I)	Returns A new IItemStack with the added NBT tag	ParameterTypes IData
Method call stack.updateTag(IData, bool matchTagExact)	Returns A new IItemStack with the added NBT tag	ParameterTypes IData, bool

Method call	Returns
Method call stack.asBlock()	Returns A new IBlock object.
Method call stack as IBlock	Returns A new IBlock object.

Method call	Returns	ParameterTypes
Method call stack.withDisplayName(String name)	Returns A new IItemStack with the specified display name. Unlike the displayName setter, this only applies to this single item.	ParameterTypes string (supports color codes with "§")
Method call stack.withLore(String[] lore)	Returns A new IItemStack with the specified lore.	ParameterTypes string[] (supports color codes with "§")
Method call stack.clearCustomName()	Returns void (nothing)	ParameterTypes ​

Gets or Sets an item's forge capability data. In most cases, the tag of the stack has what you need, this is mainly for advanced use cases.

Method call	Returns
Method call stack.getCapNBT()	Returns IData
Method call stack.withCapNBT(IData data)	Returns A new IItemStack with the specified capability NBT

Method call	Returns	ParameterTypes
Method call stack.canApplyAtCraftingTable(IEnchantmentDefinition enchantment)	Returns A bool.	ParameterTypes IEnchantmentDefinition
Method call stack.addEnchantment(IEnchantment enchantment)	Returns void (nothing)	ParameterTypes IEnchantment

Method call	Returns	ParameterTypes
Method call stack.canPlaceOn(IBlockDefinition block)	Returns A bool that tells if the item can be placed on the block.	ParameterTypes IBlockDefinition
Method call stack.canDestroy(IBlockDefinition block)	Returns A bool that tells if the item can destroy the block.	ParameterTypes IBlockDefinition
Method call stack.canHarvestBlock(IBlockState block)	Returns A bool that tells if the item can harvest the block.	ParameterTypes IBlockState
Method call stack.getStrengthAgainstBlock(IBlockState block)	Returns A float that represents the item's strength against the block.	ParameterTypes IBlockState

Method call	Returns	Parameter Types
Method call stack.createEntityItem(IWorld world, float x, float y, float z);	Returns A new IEntityItem that corresponds to the newly created item in the world	Parameter Types IWorld, float, float, float
Method call stack.createEntityItem(IWorld world, IBlockPos pos);	Returns A new IEntityItem that corresponds to the newly created item in the world	Parameter Types IWorld, IBlockPos

Gets a mutable ItemStack. Its damage, amount and tag is mutable. Its withTag, withAmount and other methods will change the item itself, rather than returning a new changed item.

Method call	Returns
Method call stack.mutable()	Returns IMutableItemStack

You can find how to use these either in the IIngredient page or in their respecive entries:
Item Conditions
Item Transformers

Globally (translates the item to the new name).

ZenScript
 Copy
val apple = <minecraft:apple>;

//prints "Apple"
print(apple.displayName);

//Sets apples Display Name to "Tomato"
apple.displayName = "Tomato";

//prints "Tomato"
print(apple.displayName);

Locally (only this single item).

ZenScript
 Copy
<minecraft:coal>.withDisplayName("Black Gold");

<minecraft:coal>.withLore(["This function","requires a","string[]"]);

The maximum Stack Size is how many items fit in one Stack, for example, wool’s Stack size is 64 and Buckets’ only 16.

ZenScript
 Copy
val apple = <minecraft:apple>;
val bucket = <minecraft:bucket>;

//prints 64
print(apple.maxStackSize);

//sets apples Max Stack size to 32
apple.maxStackSize = 32;

//prints 32
print(apple.maxStackSize);

//sets apples Max Stack size to Bucket's Max Stack size
apple.maxStackSize = bucket.maxStackSize;

//prints 16
print(apple.maxStackSize);

The Hardness is how long it takes to break the referred block. Only works if the object refers to a block.

ZenScript
 Copy
val grass = <minecraft:grass>;

//prints 1.0
print(grass.hardness);

//sets grass Hardness to 10.0
grass.hardness = 10.0;

//prints 10.0
print(grass.hardness);

The damage for items that cannot be damaged is 0.

ZenScript
 Copy
val pick = <minecraft:diamond_pickaxe>;

//prints 1561
print(pick.maxDamage);

//sets the max damage of the Diamond Pickaxe to 256
pick.maxDamage = 256;

//prints 256
print(pick.maxDamage);



//Damage doesn't matter, used in recipes
<minecraft:iron_pickaxe>.anyDamage();

//With the given damage
<minecraft:iron_pickaxe>.withDamage(122);

The tag is an IData object.
If the item does not contain a tag, it will return an empty tag, never null.

ZenScript
 Copy
//creates apple with the given tag
//Removes existing tags
<minecraft:apple>.withTag({Unbreakable: 1});

//creates apple with an empty tag
<minecraft:apple>.withEmptyTag();

//removes a tag by its name
item.removeTag("tagName");

//removes all tags from an item
item.removeTag(null);

//update the existing tag
//If the tag doesn't override an existing tag, they will stay constant.
item.updateTag({Unbreakable: 1});

Returns the liquid contained in a single item (if multiple) or null if the item is no container.
Returns an ILiquidStack Object or null.

ZenScript
 Copy
val lav = <minecraft:lava_bucket>;
print(lav.liquid.name);

How many apples are there?

ZenScript
 Copy
<minecraft:apple>.anyAmount();

//1 Apple
val apple = <minecraft:apple>;

//2 Apples
val moreApples = apple * 2;

//3 Apples
val evenMoreApples = <minecraft:apple> * 3;

Returns a weightedItemStack with the provided percentage.

ZenScript
 Copy
val apple = <minecraft:apple>;

//Creates a weightedItemStack with 100 percent chance
var applePercentage = apple % 100;

//Does the same as the above
applePercentage = apple.weight(1.0);

Returns a List of IOreDictEntries referring to this item.

ZenScript
 Copy
<minecraft:apple>.ores;

You can cast an IItemStack to an IBlock, as long as you are referring to a block, otherwise the cast will throw an exception.

ZenScript
 Copy
<minecraft:dirt>.asBlock();
<minecraft:dirt> as crafttweaker.block.IBlock;

You can also test if an IItemStack contains an ItemBlock and can thus be converted:

zenscript:
 Copy
<minecraft:dirt>.isItemBlock; // true
<minecraft:stick>.isItemBlock; // false

You can check if an IItemStack is a food item and what food properties it has.
May not work for every modded food item!

ZenScript
 Copy
<minecraft:apple>.isFood; //true
<minecraft:apple>.saturation; //0.3
<minecraft:apple>.healAmount; //4