These are really fun! I use this method for many abstracts paintings,also. First, mono print a mix of acrylic modeling paste and gel medium on Fabriano 140 lb rough artistico to create bone like textures. Continue painting wet in wet over the paper with acrylics,watercolor, and India inks to revel forms. Opaque colors are used to paint around fossil forms. Lastly emphasize bone textures by sanding the high spots. Mount on gallery wrapped canvas using acrylic gel medium as a glue. Spray with a fixative,then varnish. Let your imagination go,be inventive. My college students love this way of working. They come up great variations on this theme.