Damian's original costume may look familiar...

[theanswer]

 Frank and Grant intended to take the new plate armored look of the Bat Family a bit further than the final product. For Damian, Frank thought the old Richard Grayson Earth-2 "Bat-Robin" costume would represent his desire to grow into the cowl perfectly, but it was later decided that both costumes were too radically different from the familiar and ultimately didn't suit the characters.



Just for comparison, here is the inspiration.