You don't really need the light on until the seedling actually breaks the soil. There, it'll expose it's cotyledons [ the round leaves ] to begin photosynthesis. Oh, and some people do like to germinate using the papertowel method, I being one of them. I prefer this because it really roots out the weak seed stock from the good --- and it gets them above the soil a bit quicker what with already having a taproot ready to search for water.