Client: DC Comics
Media: Pencil & India Ink on Strathmore 500 Series Illustration Board, then colored with Adobe Photoshop CS2
Promotional giveaway poster for DC Comics at 2008 conventions. A big job. Woof.
The reason why Catwoman is the only character wearing black (DC wanted everyone in white) is because DC didn't want Catwoman included! Her book was being canceled at the time, and it was felt that they shouldn't be 'promoting her' as a result.
I argued and argued for her inclusion, and decided to draw her in for my own benefit, all the way on the end, knowing I could Photoshop her out in the coloring phase. Typically when DC saw Catwoman, they loved her and asked if she could be included. This was about 12 hours before the piece was due.
Catwoman was only penciled at that point, so I knew I could ink her in a black dress and there'd be no time for it to be changed, so.... there you go.
If you're looking for a STORY reason why Selina is in black, not just my behind-the-curtains explanation: Selina gets invited, at the last minute, to this 'Women of DC' photo-shoot, and is told to wear white. Out of spite, she wears the blackest dress she's ever stolen. She DID bring a white cat, though!
From the left side: Catwoman, Barbara Gordon (seated), Zatanna, Black Canary, Powergirl, Wonder Woman, Supergirl, Batwoman (seated), Vixen, Poison Ivy, & Harley Quinn.