ShipScript has been an eBay Community volunteer since 2003, specializing in HTML, CSS, Scripts, Photos, Active Content, Technical Solutions, and online Seller Tools.
Media mail is for educational material and is subject to postal inspection. Items shipped as media mail and found to contain unapproved items, will be charged at the priority mail rate.
Empty stamp albums or holders would not qualify as media mail.
There is a nice summary at the bottom of this page:
https://www.pitneybowes.com/us/blog/what-can-be-shipped-via-media-mail.html
The USPS list is here:
https://pe.usps.com/text/dmm300/173.htm
