Rust drawing

Now I am one of those people that can be skeptical in using different methods and materials within my work.

I'd done this in college a few months ago and never rated the effect of the final outcome.
Fast forward to now and I wanted the same colour as I had previously so tried it again within the house and this is what had appeared.
What I had done was raided the garage for anything that I could find which was going or was already rusty and set them on material. I put paper behind for leakage and sprayed with salt water.
Still very unsure whether it was how I wanted it to turn out but I am sure I'll be trying this again!