I am using Adobe Acrobat Professional v. 9, on Windows 8.1. Here's a minimum (not) working example:
\documentclass{article}
\usepackage{mdframed} % noteboxes, boxes, etc.
\newmdenv[linecolor=black]{notebox}
\begin{document}
\section{Introduction}
\begin{notebox}
Here, I am testing out a notebox.
\end{notebox}
\end{document}
This is the output of that example:

It is worth noting that the zoom level of the PDF affects the output. The above screenshot was taken at 150% zoom. Here it is at 100% zoom:

Everything works well in Foxit reader, at all zoom levels:

For some reason though, it is difficult to show the top and left-side lines in the screenshot (even though they appear properly in the PDF viewer), I think because the framed environment has a slight "shadowing" effect that seems to mess things up. Here's the screenshot at a much higher zoom level (1200%), again from Foxit reader:

Here is a 1200% level screenshot from the same region in Adobe Acrobat. Surprise! It shows up:

So I am a little confused, and not quite sure what is going on. **How can I set up a robust "boxed text" environment?
mdframedboxes display robustly given the failings of pdf viewers, one should bump up the lineweight of the borders? – bzm3r Apr 13 '15 at 01:57mdframed. – Apr 13 '15 at 04:09