# Include guides for staples within binding offset

I’m dealing with this setup:

\documentclass[twoside]{exam}
\usepackage[
letterpaper,
twoside,
bindingoffset=0.5in,
inner=0.75in,
outer=0.75in,
top=0.75in,
bottom=1in,
footskip=.5in,
]{geometry}
\begin{document}
Text text tex.
\end{document}


On the first page, I would like to include two dashes within the binding offset, to serve as guides to where to staple the packet.

I’ve looked at several other posts and none of helped. I imagine it will involve TikZ, but I’ve also seen the background package come up. How can I achieve this goal?