Large legal sized
envelope, customarily of a orange-y yellow tan color (manila colored) usually for sending legal documents
back and forth. Often has a nifty string tie thingy
or sometimes a fragile metal closure which is designed to break after one use
They make them with the metal closures now because the conspiracy of manila envelope makers want you buy more. The old nifty string closure manila envelope companies went out of business because people would buy one manila envelope and use it for the rest of their natural lives.
Waste is profit. Down with the man!