Thanks, glad you noticed that part. I'm trying to get away from static wing anatomy (always open and wing skin fully stretched), it only makes sense that they would crumple up and fold onto itself. Here...I was imagining it like fabric, like a blanket.
I see. Fabric is good choise, but again, here comes drapery still lifes. Hmm, for advice... Hm, If I were you I were looking for bat photos and pterosaurs recontructions. [link] To achieve more natural efect easier.
While i know it's digital, it looks close to traditional pencil drawing. Oh and i just don't know why, but the area where rear legs connect to the body seems strange to me...i don't know if it could be done in any other way in this particular picture...but it just feels strange. Dunno why.