The term 'kind of folder' can be solved by two crossword solutions: MANILA (6 letters) and spam (4 letters). MANILA is a type of folder made from a type of fiber derived from the leaves of the abaca plant, which is native to the Philippines. It is usually yellowish-brown in color and is often used for filing documents. Spam is a type of folder that is used to store emails that are sent to multiple recipients. It is typically used to store emails that are not wanted or are considered to be junk mail.