Johnny Key iPad Case

Below is the progress on creating my Speck case for my iPad 2. I discovered using the Montage app works very well for covering the knobs. Also, must use cropped images form the same photo, otherwise the light/dark is off. Next imported the collage photo into Sketchbook Pro, an app I love to sketch with. I admit I don't know the app very well, but couldn't create a color palette. The tools are too solid or funny textures, i don't want to replicate a painting just add another layer with color lines. I'm going to try the Brushes App next but, loving all the bright colors.