Rust dying with tea or vinegar

I have always attempted rust dying with old metal and white vinegar but Alic Fox's book introduces a new method - using tea with iron. In fact she advocates that different blends of tea (Earl grey, green, fruit) will give different "rust colours" in the end result. I was keen to try this out so I started off with the tea and iron - these are the more brown shades in the photo. And then I splashed some white viegar onto one part of the metal encased in the coton - these are the bright yellow/orange parts. It is important to thoroughly rinse the fabric in salted water to stop the acidic deterioration of the fibres when you are through the rust dying process