PDF signatures between Mac & Windows

Why do signatures I sign on PDFPenPro not display on adobe or any other PDF app on windows? I’m not trying to digitally sign anything with a formal certificate, there are just occasional documents that I need to sign for work so they can be printed by someone else. I always get emailed back saying my signature isn’t showing up. Without going all out with digital signing (too expensive and unnecessary for what I do), is there an easy way I can simply sign something that someone on windows can actually see my signature?

I’m not familiar with PDFPen, but several pdf apps have a way to save a “flattened” pdf. This incorporates annotations such as signatures into the pdf, rather than on a layer. Might be an option for you.

To wit;