Small plate with artists' signatures

This is a china plate about 4" in diameter with the apparent autographs of 12 very well known artists on top of the glaze. The artists include Picasso, Vincent, Matisse, Renoir, Goya, Tamayo,Rodin, Diego Rivera and others. It can be seen that the ink of the autographs is actually on top of the glaze (placed after firing). How can I authenticate this piece as something that was actually signed by these artists? Thank you for any direction that you might offer. I can email photos, but the file type is not compatible with this site. Thank you again,
Kelly Sanchez
(956)792-3637