Natural latex rubber remains one of the most popular materials used in making balloons. Since it is also commonly available as a craft product---it's sold in costume and magic stores---you can use liquid latex to create your own simple homemade balloons. Use this project to teach kids the basics of rubber production, or just enjoy making your own balloons from scratch.
Soften the paraffin in the microwave. Break it up into the smallest pieces you can (use a chopping block or cheese grater), then place the pieces in a microwaveable container. Cook on "high" for 30 seconds at a time until the wax starts to look shiny and soften.
Shape the paraffin into a mould shape for the balloon. While it's still warm from the microwave, shape the wax like clay into a shape similar to an uninflated balloon; oblong, with a knob at one end. Press the knob end against the counter top to shape the wax so that it will stand up on its own.
Mix acrylic paint with the latex give the balloon colour. Use a ratio of one part acrylic paint to 30 parts liquid latex, and stir until the paint is evenly distributed in the latex.
Coat the wax mould with latex using a craft brush. Apply a thin, but even and complete, coat of latex to the wax mould, covering every part of the mould except the bottom of the knob where it touches the counter.
Let the latex dry. You'll know it's fully cured when the liquid changes uniformly to a darker colour and becomes firm to the touch. (It will remain sticky.)
Apply a second coat of latex. Let this dry as well.
Dust the outside of the latex with cornstarch or baby powder. This will keep it from sticking to itself as you remove it.
Remove the finished balloon from the wax mould. You may be able to peel the latex off the wax without breaking the mould; if not, break up the wax with your fingers while it's inside the latex, then remove the pieces. (You may need to turn the balloon inside-out for this.)
Melt and rebuild the wax to make additional balloons.