<p>I have a printer with a 0.1 mm typical layer thickness. Of course I can choose some different sizes in Cura or other slicing software, but most prints on this machine will be .1mm. In my (admittedly limited) experience thus far, the 0.1 mm seems typical for other printers, too.</p>

<p>I want to get a sense of just how thick this is. I know about the paper trick for leveling the print bed, but my understanding is the first layer pushes into the bed a little, meaning it's less than 0.1 mm and so paper isn't a good example for the typical layer. </p>

<p>Is there a similar item with close to 0.1 mm thickness I can use to visualize this?</p>

Sure. Get a 0.1mm thick feeler gauge.
http://duckduckgo.com/?q=feeler+gauge+.1mm