I've made a few 4'x4' frames from thick wall PVC piping, painted flat black(mostly to look more professional when around clients/customers who know what 1" ID PVC pipe is, but when its black, they think its 'cool'
I made mine with elastic bungee cord inside, so they 'snap' together easily. I can use standard sized 4x4 sheers/scrims/nets,etc... Ones I don't own, but need, I can rent.
And the frames are light enough to be easily handheld ALL DAY by an assistant or in a pinch, a MUA or stylist if no asst is available