Papier mache is a French term which translates to "mashed paper." An alternate spelling, "paper mache," is also used. This versatile craft project is used for making everything from masks to pinatas, usually by forming the paper mache around a mold. A common technique for making pinatas is to dip strips of cut newspaper into wallpaper paste or a flour and water mixture, then lay them on top of a balloon. When the paste dries and you pop the balloon, you are left with a hard paper shell. However, paper mache can stick to balloons and molds, which calls for an inexpensive mold release agent.
Prepare the mold to which you wish to apply paper mache. This can be as simple as blowing up a balloon or as complex as casting a plaster mold of a human body.
Dry your mold thoroughly. If you are using a balloon, your mold will already be dry. If you are making a plaster mold, allow the plaster to set for at least 24 hours after pouring.
Open a jar of petroleum jelly.
Apply a thin coat of petroleum jelly to all surfaces of the mold using your fingertips.
Apply wet paper mache strips to the mold. When the paper mache is dry, lift it carefully from the mold or pop the balloon inside. The petroleum jelly will act as a mold release agent, keeping your paper mache from sticking.
When making a paper mache mold of a balloon, always leave enough of the balloon uncovered so it is easy to pop.