Darkest dark
 

I have a painting with a flat black background - I have not had a problem getting this before.

This time however - parts are shiny and parts are flat. It's been dry for over a month now.

The frame just arrived and it is due at a gallery by the end of the week...

It really needs to be flat color - as close as I can get it to black. Any suggestions?

It's oil by the way and I used Ivory Black.