Abstract: A system, method, and ink for printing a data carrying mark on a green ceramic honeycomb structure is provided. The system includes a printer having an ink jet print head that prints a mark, preferably in the form of a two-dimensional data matrix barcode, on a side wall of the green ceramic honeycomb structure. The ink may be a heat resistant ink that comprises a mixture of a glass or glass ceramic frit and a metal oxide colorant. An optical reader is provided for determining if the data is accurately reproduced in the printed mark, as well as any noise factor which may be present due to defective printing. The system includes a turntable that positions the green body for the printing operation, and then rotates the green body to position the printed mark first in front of a dryer, and then in front of the optical reader to determine the quality of the mark. Marked green and ceramic honeycombs are also provided as well as a method for repairing a defective applied bar code on a honeycomb structure.