A blackboard is a popular prop in my stock photography. I have several of them in my studio. There were used in a few hundreds of images: (1) backgrounds and texture, (2) words, phrases, questions handwritten in white chalk, (3) sketches, diagrams, flowcharts, (4) acronyms explained with sticky notes and handwriting, e.g., SMART, PRIDE, or TEAM.
The recent series of images featuring my favorite vintage slate blackboard is devoted to word clouds related to different subjects or concepts: Thanksgiving, New Year and Christmas greetings, computers, internet and technology, health and wellness, science, business. There is just a small sample of that above.
If you prefer a more modern look I have a series of word clouds on a digital tablet.
Related posts:
Wood Letterpress Typography on a Digital Tablet
Christmas and 2014 New Year Greetings in Royalty-Free Typography
Custom Designs in Vintage Letterpress Wood and Metal Types