|My children painting outside|
Of course, there's also the DIY route. By doing it ourselves, not only do we save money, we can also tailor it to our specific needs. This double sided outdoor easel is one example. I must have seen this idea somewhere online but can't remember the site at the moment. It was quick to put together, very inexpensive compared to store bought, it is portable, foldable, and easy to store.
I bought two sheets of plexiglass from the local hardware store and used a clear packing tape to hold the sheets on top. No paper needed. The kids paint directly on the plexiglass and I take a picture of their work for posterity. I then hose it down, dry it, and fold it away for next time.