I did this cross stitch for my wonderful Mum when I was younger. Interestingly after some years, a rust mark appeared on the cloth. I had obviously placed my needle there while I was stitching. The needle was not rusty at the time - but microscopic remnants of the metal were left behind which have rusted over time. Not what I expected. So the lesson here - don't store your needle on your cloth while you are cross stitching, doing a tapestry or just sewing in general. Your work might end up tarnished by rust.