Engineer's Blueprint

The Engineer's Blueprint (previously known as the misspelled Engineers Blueprint) is an item added by Immersive Engineering. It is used in the Engineer's Workbench; putting it in the main slot of it will the crafting of special items. Different blueprints exist for the creation of different items.

Crafting Components
The Crafting Components design can also be obtained by trading with the Engineer Villager.

Common Projectiles
The Common Projectiles design can also be obtained by trading with the Engineer Villager or from an Engineer's House.

The Common Projectiles design is used to create Casull Cartridges, Armor-Piercing Cartridges, Buckshot Cartridges, High-Explosive Cartridges and Silver Cartridges.

Specialized Projectiles
The Specialized Projectiles design can be obtained by trading with the Engineer Villager or from an Engineer's House.

The Specialized Projectiles design is used to create Dragon's Breath Cartridges, Homing Cartridges, Wolfpack Cartridges and Phial Cartridges.

Arc Furnace Electrodes
The Arc Furnace Electrodes Projectiles design can be obtained by trading with the Engineer Villager or from an Engineer's House.

The key is to trade a lot with the Immersive Engineering villagers so they will level up and trade more things with you. After a lot of trades they might sell you the Arc Furnace Electrodes Blueprint.

The Arc Furnace Electrodes Projectiles design is used to create the Graphite Electrode.

Super Special BluPrintz
The Super Special BluPrintz is a special blueprint that can be obtained by trading with the Engineer Villager or from an Engineer's House. It will mirror one of the other blueprints, but with the modified name "Super Special BluPrintz" and the tooltip/lore "Congratulations! You have found an easter egg!".