Rust-not just a Canadian Crayola color from 1987

In 1987, Crayola produced for the Canadian market a set of metallic crayons-which included the color Rust.

This post isn’t about that, what it is about is the “rusting” of stamps and envelopes, also known as foxing. I knew about foxing from my experience in the way back-but rusting is new to me. This is the process by which a stamp or cover is attacked by mold and funguses. This can turn the stamp/cover various colors (orange, black, green, and blue) and is usually as a result where the items were located and stored and how humidity affected the items. Here are two images of a stamp and of a cover with rust.

I have only been aware of the orange and the black spots. The mold and fungus attacks the glue etc. and will make the item worthless. As I dove into the hobby I picked up just a few items that had significant or faint rust. I destroyed them-a couple of covers I put aside and I reexamined and I can’t determine if it is rust or a stain and I will need an UV light to do so-so I have placed them in plastic non-acid sleeves and isolated them from collection for further observation. These images really give you an idea of what to look for-fairly easy to do so.

While no stamps were involved I did lose some stamps on cut paper and covers. I am bummed but thankfully it wasn’t much and a lesson learned. So what were the lessons learned?

1. If a cover is listed that has interesting franking and bidding is slow to nonexistent-it is probably because there is rust, or another fault.

2. Use the zoom on the Bay to examine every inch of the cover or stamp that is listed.

3. Don’t be afraid to pass on something if you detect what you think is rust unless you get it for dirt cheap and you can examine further to determine if rust or not, and if it is you aren’t out of much $$. If it isn’t, rust then you picked up a steal.

4. Spanish covers seem to be hit hard-again from the environment.

Here is one cover I destroyed-really broke my heart as I loved the franking.

I have read various posts and threads on whether to remove the rust or not-and I understand both sides, but as some have pointed out the issue is when these cleanings are not disclosed when the item is sold off. For me, I am not going to remove any as I threw them out. Could you freeze them to stop the fungus/mold? Probably just end up with a soggy piece of paper.