Some users pointed us a problem with Black Ink since the latest Windows Creator Update like this post and this one
From what we understand there is a problem with the Window compositing when there's some transparency.
We will work to fix this issue for the next update but for now here the instruction to workaround:
Open the Config.xml file with a text editor (On Windows 7/Vista):
C:\Users\MyUserName\AppData\Roaming\Bleank\BlackInk\Config.xml
Note: If your "AppData" folder is hidden and doesn't appear in your user folder, simply enter "%appdata%" in any explorer window.
On Windows 7/Vista Steam :
C:\MySteamFolder\SteamApps\common\Black Ink Steam\Datas\Config.xml
On Windows 7/Vista Steam Demo :
C:\MySteamFolder\SteamApps\common\Black Ink Demo\Datas\Config.xml )
You should have something like that:

So change the entry IsFullscreen into true , Maximized into true and Composited into false and save the file

Then restart Black Ink!
Redo the same modification each time Black Ink isn't displayed when started.