I’ve just made an experimental piece as I wanted to answer a friend’s question which was “will PVA stiffen felt”? I created a very quick wet felted bowl using a single layer of grey Norwegian wool which was lightly felted and then soaked in a 50/50 solution of PVA and water. It was placed over an upturned glass bowl until it dried out. It isn’t rock hard but certainly stiff enough to give it some body. I can’t say that I particularly like it as a finished piece, so it will probably get washed out and recycled, but the PVA did its job so my friend got their answer and I’ve learnt something for future use.