The mezuzah should be placed in a case for protection. It should be rolled from left to right, so that the Sha-dai written on the outside is visible. It should then be placed right-side-up inside the case, with the Sha-dai in front. If you do not have a mezuzah case, wrap the mezuzah in thick paper or some other material.
Mezuzahs are often aquired from the sofer or Judaica store already rolled and encased. It is important that it is obtained from a reliable source, so that you can be sure that it has been placed properly. Sometimes mezuzah cases are sold without anything inside!
There are many types of mezuzah cases available today, from plain plastic cases that cost a few cents to artistically decorated cases in a range of precious materials. While it is a good thing to beautify the mitzvah, remember that the most important thing is to invest in the quality of the scroll inside.
Can the Case be Transparent?
Depending on where the mezuzah will be affixed, you can or cannot use a transparent case made of glass, lucite etc. In these scenarios a transparent case should NOT be used:
• If it faces a bathroom.
• On a doorpost or archway inside a bedroom.
• On any doorpost or archway of a room where babies’ diapers are changed.