Joker sketch cover process

Even for something like a "sketch" cover unless I have the idea concrete in my mind's eye, I try to plan stuff out and that involves numerous steps. Here's some pics detailing the progression from thumbnail sketch to final painted piece. My original plan was to do the final piece in Prismacolor markers, but I thought I'd try painting one for once despite some fears about whether the paper covers could handle acrylics. I'm happy to say they did really well and it opens up a lot of possibilities for me on future sketch covers. But here's some of my initial marker sketches for you to check out....

For the next step I used a lightbox to roughly trace my last marker sketch. Then I mixed up some reddish purple and acrylic matte medium to lay down an underpainting. Since 1997 I've used Basics Acrylics for painting... I've used a lot of different brands but to me they are just the perfect consistency - I find a lot of other brands to be too watery for my tastes and I mix everything using primary colors and white. But I'll start by mixing up a dark purple and paint darks and lineart really quickly, then cut back over it to clean it up. Here's a couple pics of the painting in various stages.

Here's how the final piece ended up. I put it up for auction on Ebay if anybody's interested.....

Goad Batgirl/Joker sketch cover auction