The Rust Fabric Dying Recipe
Natural Fibre (for me this is usually 100% cotton fabric), white vinegar and rusty objects.
Take one or several rusty items and wrap/sandwich the item into the chosen natural fibre. Place the wrapped item into a seal-able plastic bag and pour enough vinegar over until the item is completely covered. Seal the bag and place in the sun for a minimum of 48 hours (I usually loose track of time and they end up being in the sun for 1 or 2 weeks). Unwrap the fabric, remove the rusty items and rinse out the fabric, soak in a salted water solution for an hour or so and then rinse the fabric again.