1 Making paper clay :
Take some paper / cardboard and blend it with water for getting a mix of thin pulp into the water.
Take out the water by pressing the mix into a tote bag / fabric.
2 Making some glue.
Boil some water, put it into a blender.
Add some rice flour until the texture is more a less similar as a good Bechamel sauce.
3 Mixing the two ingredients in a bucket with a ratio 1/3 glue for 2/3 pulp.
Add more glue if it feels too thick, add some pulp if it feels too liquid.
4 apply the clay and be sure to let it in a place it can dry.
Find the press plans here.