Procedures:
1. Tear the tetra-paks into tiny pieces, then soak them into a pail of hot water for about 30 minutes. Put a handful of the soaked paper into the blender and mix until mushed.
2. Pour the blended pulp into a measuring cup. Pour roughly 3 cubic centimetres of water into the pan. Place the screen into the pan and pour 1 cup of paper pulp onto the screen.
3. Spread the pulp evenly in the water with your fingers. It should feel kind of mushy. Lift the screen and let the water drain.
4. Lay the pulp-covered screen face down on a cloth or in between some newspapers. Lift the screen away, leaving the paper pulp on the cloth. Cover with another cloth and iron it, or use a rolling pin to flatten. Press out excess moisture. Let the pulp dry for at least 24 hours.
5. Once it is dry, it is ready for use.
Source:
http://www.ecokids.ca/pub/fun_n_games/printables/activities/assets/science_nature/paper_making.pdfscience_nature/paper_making.pdf