777. A Tallis

Shabbos 19:20

A person is permitted to wrap himself in a tallis that has untied strings at the edges even if they are long and not particularly attractive because the strings are subordinate to the garment; one who wears such a thing is indifferent about the strings. Therefore, if a person goes out wearing a tallis whose tzitzis are not halachically valid, he is liable. This is because these strings are important to the wearer; he is concerned about completing what they lack so that they can be valid as tzitzis. If the tzitzis are halachically valid, it is permitted to go out wearing this garment both by day and by night. Halachically-valid tzitzis are not considered to be a burden because they enhance the garment. If halachically-valid tzitzis were a burden, one would be liable even for wearing the tallis on Shabbos day since if a positive commandment is not punishable by kareis (excision) if violated, it does not take priority over Shabbos.

Shabbos 19:21

A tailor may not go out on Shabbos with a needle stuck in his clothes, nor a carpenter with a splinter of wood behind his ear, nor a weaver with wool in his ear, nor one who cards flax with a string around his neck, nor a money-changer with a coin in his ear, nor a dyer with a sample in his ear, though if one of these professionals goes out with such a thing, he is not liable. Even though transporting in this manner is common for people in these professions, he is not liable because he is not considered to have transported the thing in a normal fashion.