interior design inspiration- shades of gray

Isnt this picture the sweetest thing you've ever seen? I LOVE it. I couldnt seem to locate the original source for this picture, if you know where its from... please share!  I am really curious to read how they did the calendar. :) It looks like they tinted some chalkboard paint in various shades of gray, and painted the squares. I'm sure some masking off was done to get the straight squares... but I think this would be cute with imperfect squares too. :) When we sell our house and move... I am soo planning to do a gray and yellow theme. This idea works perfectly, and I just might implement it! :)