Mattint Shark
A 'tint' is a pale tinge of colour, just a hint.
Matte is the finish of a surface, compared to a gloss or satin finish, matte offers the lowest light reflection. A sealed surface will look natural, unsealed.
Therefore, PaperArtsy Mattints are a sealant, totally transparent tinted layer (and adhesive) with a matte finish and a slight hint of colour.