Determine whether the piece is on glossy paper or on matte paper. Originals will be on matte paper, while reprints will be on glossy paper. Glossy paper will be reflective and smooth while matte paper is porous and slightly rougher to the touch.
Look for the art work's print number. Each of Gutmann's works will have a number associated with the specific print. This number identifies the number of prints the artist made of that piece.
Find the "Gutmann and Gutmann Copyright, New York, NY" seal. Each of Gutmann's pieces has a copyright seal.
Locate the title of the print. It will be in block print below the painting, usually with the copyright date beside it. New prints have the title in script rather than block print.
Check to see whether the margin has an embossed stamp. Not all prints have this. These are the plate markings.
Look to see whether the print has a poem about a girl sharing her ice cream with her dog on the back of it. Two of Gutmann's pieces, "The Reward" and "In Disgrace" have a poem that goes with those pieces in the early 1900 prints.