The word pysanka comes from the verb pysaty, "to write" or "to in scribe", as the designs are not painted on, but written (inscribed) with beeswax.
They are created using a wax resist process, where beeswax is applied to the eggshell with a traditional tool called a kitska. Once waxed, the egg is placed in a dye bath. This process is repeated, going from lightest color to darkest all the while waxing in between.
At the end, the wax is melted off to reveal the final design.