Negative painting experiment

Looking for inspiration in my pile of painted paper oddments, I found a Bockingford watercolour paper sample which I had at some time randomly coloured with fluid acrylics and then glazed with white pearlescent acrylic ink.  I used a simple poppy image from a previous project; this was on tracing paper so I was able to position the flower heads as close as possible over magenta areas of the background.

I started by negatively painting with white acrylic, but this wasn't the effect I was after.

6" x 8"

Next step was to outline the image
with a black Posca pen

I then tried out a black gesso background -
(the tracing image is shown on the right)

Finished image 4" x 6"
Washes of fluid acrylic have been used to add some detail

It needs another coat of black gesso to smooth out the background; without the Posca pen I doubt I would have been able to achieve a very clean outline to the image.  It is difficult to show the effect of the pearlescent glaze, but it certainly stands out against the black.  I will have to try this out on a slightly larger, more complicated image.