Easy peasy textures for you to use. Gumroad's policies on filesize means that I'm including all textures as images, and not formatted for Photoshop's pattern layouts. But on the plus side, these are all software ambiguous. This pack includes full resolution scans of a wide variety of security envelopes, as well as cleaned tiling versions.
Drag them into your software of choice! The tiling sets would benefit from being added to Clip Studio'smaterials, or saved as patterns in Photoshop.
Big thanks have to go to Dean Sudarsky, he was the one who intially donated all the security envelope scans, and this simply wouldn't be possible without him!