Gather the item to copy, silicone mold-making rubber, mixing cups, stir sticks, mold box materials, release agent, and a scale or measuring tools
Clean and dry the original item thoroughly
Build a mold box that leaves space around the item on all sides
Secure the item inside the mold box
Apply release agent to the item if needed
Mix the silicone according to the manufacturer’s instructions
Pour the silicone slowly into the mold box from one corner
Tap or vibrate the mold box to release trapped air bubbles
Let the silicone cure for the full recommended time
Remove the mold box after curing
Carefully take out the original item from the silicone mold
Trim any rough edges if needed
Wash and dry the mold before use
Use the mold with compatible casting material
Store the mold flat and away from heat and sunlight