Originally Posted by gullfo
most times the "frameless" finish (fairly common in retail spaces where lots of panels are used for acoustic and/or decorative purposes) use 6lb/ft3 (96kg/m3) since the 3lb/ft3 (48kg/m3) is too soft to use - but the 6lb might not be what you need for the absorbers... also the dipped edges mean you lose some of the nice effects that exposed edges give you (not a concern if your frames weren't going to be open on the sides anyways).
All great points from Glenn as usual.
They are easy to build with this method, but you are stuck using thin pieces of fiberglass, and if they need to be moved around often, the fabric can start to tear. This also doesn't make for very sturdy panels, and resale value is pretty much impossible should you later buy or make new ones. However, for spot treatment on remote recording locations or something, they'd be fine!