Making dollies into bowls and need a good glue
Mod podge makes a stiffy. You coat your dollies in it and then drape over a bowl for shape. I have also seen them made with cement, again coat with the cement, wring out and lay over bowl to dry.
A 50/50 mix of any white glue will give you the same thing for less.
Old fashioned way is starch and water then pot pretty side down over a can and let dry