In my studio, I have 3/4in plywood walls which allow me to use hefty screws at 12in intervals (1/2in ply would work just fine as well). You can use screws at different heights as well if you want to move your work up and down vertically, or if you want to hang work in a grid. Also, when you have plywood walls, you can screw in and out easily without having to aim for a stud, which is what you would need to do if your walls were made of drywall. I have found this "system" to be the best for me. You have full control of height and width between the screws in the wall, and they are very sturdy. Panels that are 36x36in or larger, made of Baltic Birch are getting to the weight and size where such a system is needed. If you work smaller than 36x36in on panel, you can certainly get by with dry wall.
Another solution for those with drywall - you can purchase 1x2in wood (this is approximate - there are many sizes of beams to choose from) cut to what ever custom length you want and attach with screws to the studs in your wall. Then, although you don't have plywood, you have the thickness of wood you need to hold any weight of panel you work on. I used this system in my former studio and it worked just great!