Mini sheet protectors is sincerely not a defined term. Even though over the years it seem like half the size of a letter size is considered a mini size sheet of paper. It make sense so we named our sheet protectors that holds a half folded letter size sheet of paper: Mini sheet protectors.

It will then hold a 5.5 wide by 8.5 inch high sheet of paper or photo. For more information feel free to use the link about or use the picture to the left to make a purchase at Keepfiling.com

What is the name of 14 x 8-1/2 paper size ???

Legal size document sizes are very common but often on printers and copy machines only refer to this document size is the actual size of the document and not the historical name. Unlike "Letter Size" which more often is written both as 8-1/2x11 inch as well as the term Letter Size.
Once for all Legal size documents is the same as documents made in the size of 8-1/2 x 14 inch. For more information on the legal size document format check this blog as well as this this page from Keepfiling listing all available legal page storage options: Keepfiling legal page options.  There are other pages there concerning binding options that can be check-out as well. Happy filing.