In authenticity determinable printed matter according to this invention, a
background image portion and at least one message image portion are
printed on a surface of a base member. The background image portion has a
first line drawing which is arrayed in a first direction and printed by
an ink with a specular gloss to have an ink layer thickness. The message
image portion has a second line drawing which is arrayed in a second
direction and printed by the ink with the specular gloss to have the ink
layer thickness.