Teachers on Instagram have asked me one particular question more than any other: where did you get those whiteboards?!
I love getting the question because I love giving the answer. A few years ago I was extremely close to buying expensive whiteboard material. On a whim I went to the teacher store instead (Lakeshore Learning in Saugus, MA) and found those wipe-off posters meant to be used as a sort of homework or announcement board. I bought six of them at about $3 or $4 each and stapled them to my back corkboard. They've been FANTASTIC for a few years now. If you were to get a close look you'd notice that they're starting to wear and tear a little bit so I'll probably buy new ones for next year. Looks like they're costing me about $20 every few years - not expensive at all!
Here are a few pictures I found online of the type of wipe-off poster I'm discussing. Not exactly the same but very similar:
I highly recommend them!