How To Store Embossed And Non-Paper Stamps

Hi! Feel free to move this post to its proper section. I store my stamps in generic brand binders using Lighthouse VARIO and VARIO+ stockpages, which seems easy to manage. However for the few embossed stamps in my collection: some from the turn of the 19/20th century (Austria & Russia), some more recent non-paper ones like the embroidered stamps of Austria, Italy, and Taiwan, I am afraid that long-term pressure from the stockpage itself and from the pages above, may flatten the embossing. Is this a legitimate concern, and how do you archive your embossed and non-paper stamps.

There is also the 2006 silver Marianne stamp from France, its original packaging is apparently not airtight, and could become tarnished, are there commercially available airtights for stamps (as they have for coins).

Thanks!