I have no idea what Gabardine is. But this is the color of the strap that comes on the 5111R. I would consider it a matte chocolate. You can also look at the Patek web site for the color. I'm a bit curious as to why, since Tiffany is a Patek dealer, they can't just contact Patek to get the proper strap for the watch.
I changed the strap on mine to a glossy (or semi-gloss) black for a more formal look.
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