Help Identifying Embossed Stamp On Envelopes

Hello, so I'm new with stamp collecting and wanna get better ideas of all things stamp. I've come across a few embossed stamp on envelopes and can't seem to find any info about them. If I could get some feedback on them or links to check out to get more info that would be really great! I appreciate you taking the time to giving some inset to a newbie. Thanks

You can find these in the Scott Specialized Catalog. Your local library may have copy
Oh, and welcome to the forum


Peter

Try this site. It gets you most of the way there.
http://dubinweb.com/index.html

Going back to basics, these are known as Postal Stationery. From your photos it is unclear whether you have the entire envelope or just the cut out of the embossed image. If you have the complete envelope it is known as an "Entire" and if you only have the corner image it is known as an "Envelope Cut Square". These are the terms you need to know if you go to your library and find the Scott USA Specialized catalog previously mentioned.

I have the full envelope of them I just wanted to get close up photos. Also thank you for that website it's really good information!