Makes the Crafter block retain 1 item in each slot, preserving your recipe pattern as a template.
Place your recipe ingredients in the Crafter with at least 2 of each item. The Crafter will craft normally until any slot reaches 1 item, then it stops - preserving that item as a template.
Example: Put 10 planks and 5 sticks in a Crafter set up for crafting sticks → planks recipe. It will craft until one ingredient hits 1 item remaining, then stop. The remaining items lock in your recipe pattern.