1. A frozen loaf can be used for lechem mishnah because
    it can be defrosted and eaten within a short time. If it is not damp it can be
    placed alongside a large pot standing on the fire. If it is damp from melting
    ice, it must be wiped to avoid cooking.
  2. A loaf that is so hard and dry that it cannot be eaten as
    it is can also be used for lechem mishnah because it, too, can be made
    edible within a short time by soaking it. But a loaf that is moldy cannot be
    used for lechem mishnah.
  3. If the loaf that is being used for lechem mishnah is in
    a plastic bag (or any sort of wrapper), it is correct to remove it before
    making the blessing over bread so that the two breads touch each other. On
    Pesach, some poskim hold that the three matzohs should be separated because
    each matzah is a mitzvah in its own right and has its own special
    significance. But everyone agrees that the two loaves of lechem mishnah
    are a single mitzvah and that they relate to a single idea. According to the
    Magen Avraham, a person should remove gloves before making a blessing over
    bread even during the week because he should be in physical contact with the
    bread. That is another reason why it is correct to remove the lechem
    mishnah
    from its wrapper before reciting the blessing.
  4. A person who cannot eat a kezais of the lechem
    mishnah should at least taste it.
  5. If there is a tag on the lechem mishnah, it should be
    removed with some of the bread in order to avoid tearing it and breaking
    letters. Since this removes some of the bread, and the lechem mishnah
    should be a whole loaf, the tag should be removed after reciting the blessing.
  6. If chalah has not been taken from a loaf it cannot be used
    for lechem mishnah in Eretz Yisrael. It is forbidden to remove chalah
    on Shabbos, and in Eretz Yisrael it is forbidden to eat from a loaf before
    chalah has been removed. Since the loaf cannot be eaten, it cannot be used for
    lechem mishnah. But in the diaspora, the halachah is different. A loaf
    can be eaten before chalah is removed. Therefore, even though it is forbidden
    to remove chalah on Shabbos, a loaf from which chalah has not been removed can
    be used for lechem mishnah in the diaspora. The chalah is removed on
    motzei Shabbos.