Tried product photography...

Quick edit in Lightroom. Face isn't in focus and not sure if WB is correct.

This is about as black as I can get it and still retain some lighting detail.

This is a somewhat similar method I use for white balance and syncing to multiple photos. I also use Whibal cards too. It is a old video with a older Lightroom but is still applicable.
https://www.youtube.co​m/watch?v=0cvnyJDicDs

If you have Photoshop, look up some youtube videos on 'photoshop photo stacking'
https://www.youtube.co​m/watch?v=JC3ZmfUnA_E

If you don't have a macro rail then put your camera on a tripod focus at the beginning of the subject and switch to manual focus. Now you can slide the tripod gently and evenly toward your subject a little at a time taking photos at a certain increment, say 1/4". If your tripod does not slide easily put some paper under the feet to remove some of the friction. It is a crude way of doing it but should get you good results without spending money.