Jewish law discusses different kinds of fuels and wicks which are invalid for use on the Shabbat, because the flame that they produce is jumpy and unstable. Therefore, there is the concern that perhaps one will try to adjust the flame to stabilize it - and this is forbidden on Shabbat.
All candles which are manufactured today emit a clean, stable flame, and are therefore kosher for Shabbat candles, even if they contain non-kosher (for eating) ingredients.



Is it permissible for a man to use a lighter to light shabbos candles for his woman so she won't violate the shabbos by putting the lighter out? I understand that men have grace periods. Can the man put it out before she says the blessing?
The woman may light candles with a lighter herself, no need for a man to do it for her. She does not violate Shabbos by putting out the lighter; she can set it down as usual for it to turn off on its own.