ithuriel

I don't have much experience with them, but at least the zerust brand claims to be acid free and ph neutral https://www.zerust.com/products/vci-paper/?utm_source=google&utm_medium=cpc&utm_campaign=g-zerust-nam-us-en-non-brand-exact&utm_content=product-pages&gad_source=1&gad_campaignid=22285751022 The idea of plastic wrap just makes me uncomfortable, ide rather something that "breathes" in case any humidity finds it way in. However many shinken do come with the blades heavily oiled and wrapped in plastic....so maybe those concerns are unfounded.

Have you thought about using something VCI paper(brown paper coated with an anti corrosion agent)? Maybe wrap the blade and store it in like a silicone treated rifle sock?

Looking to do some engraving and am having trouble finding some plain fuchi/kashira....ideally in copper but brass would be fine as well. Looking for something new production ~$75-150 range Thanks!