Drawing on a blackboard

I would like to create

I'm trying to create a video where I have a blackboard background throughout and add words, charts and graphs etc with a v.o. 

How can I create this so that the chalk board remains in place (without being drawn in each time) and the hand just draws the graphs and writes the words?

A google search for "videoscribe blackboard" brings back a number of results including :

http://blog.videoscribe.co/blackboard-animation-videoscribe-can-do-that-too/

http://blog.videoscribe.co/blackboard-videos-image-filters-other-new-effects/

-Mike (videoscribe user)