Rust printing; well it's certainly a revelation! I didn't quite expect this.
I wrapped some crochet thread around the linen which was wrapped around the tin can. The white circle is from the top of the tin can, on which I placed a ring-pull lid. I expected some colouring to develop there. But it gives an effective contrast to the patterned areas.
And wrapped around the can, the linen looked like this. The can is nicely rusted now, so it's ready to have another piece of fabric experiemented on!