All boards are intended for indoor use or protected areas. Blackboard/Whiteboards are framed and come with optional glass and background card, to double as a Whiteboard. They look great on an easel, as this one does, at Cypress Gardens Retirement Village - Gold Coast.

I prefer Option 3

Chalk Art Blackboard Menu Cafe Restaurant

 
Chalk Art Blackboard Menu Cafe Restaurant

 
Option 1 . Remove the glass and use has a traditional Blackboard.

Option 2. Secure coloured card on to the blackboard and put glass to the front to use as a whiteboard.  
Option 3. Put the glass to the front with no background card. Use white or light coloured liquid chalk or a window marker directly on the glass, both can be removed easily. It gives the appearance of a blackboard, but will last for years and years with out damaging the surface.