macbook view multiple open PDFs as a contact sheet or a thumbnails view

Wow, although it didn't seem logical despite my clear search terms (including my Question, here, above) I finally discovered a MacOSX feature that has been around for years but I never knew or even tried it.

"Mission Control" and its utility to view all open documents in a single application as "thumbnails" or "contact sheet" like view!!

– none of the words I searched for are used by Apple, or therefore any third party it seems;

– it works for what my intent was and I learned about the keyboard shortcut CONTROL-arrow down and then figured out that...

– SHIFT-TAB lets me highlight for eventual selection each one of the thumbnails on screen within my chosen app.

– and the view includes the document FILENAME beneath each image.

HOWEVER, since by default the background for the window showing these floating thumbnails is the FINDER DESKTOP, your filenames may be impossible to read because of the background color/patterns which happens to be right where the text of the FILENAME is. Maybe it is a Finder appearance of my own preferences, but my filename text in Finder is white with no character outline and thus are invisible when the occur over a white area. Too bad that Apple couldn't have built in a text-color auto adjuster to ensure readability. ... seems like many versions ago that was a default. Maybe I'm mistaken....