Yeah go to a fabric store and check out their different meshes. Keep in mind more porous fabrics will pass through more light to more screens.
If you don't want to use premade frames (cost, weight) the biggest problem is keeping the fabric taut.
From experience bamboo makes a great top bar as its amazingly light and strong which means you can make it on site and get it up in the air by yourself. Also as bamboo so incredibly light you can hang it from almost anything.
As for keeping it taut, either another piece of bamboo at the bottom or fishing weights.
One thing though the fabric is a bastard to store and pack down so don't expect to get more than a few uses per screen before it looks manky and remake them.