You've put blood, sweat and tears into your project, so shouldn't your illustrator? I believe that the vividness with which a creator holds their vision should not be dulled when the viewer sees it. Everyone who brings their project to me to illustrate, in whatever medium, has been meticulous and labored hard over it, and so I should not be able to do justice to that vision with broad generalities, cutting corners, or speeding through the project to get paid and move on. I believe that viewers deserve the highest quality in terms of craft. My goal is to give it to them.