10.9 ounce (310 gram) navy, twill weave fabric in 100% wool. From the Amadeus book, fabric #300009.
Please note: pricing her is per half yard of fabric. Please consult your tailor to find out how much you'll need for your next commission. (2.5-3 yards is typical for a sport coat, 4 for a suit, but in depends on your stature, the fabric pattern, and a few other variables.)