There are different types of wicks to light any type of ghee lamp. However to light an Ashta Lakshami ghee lamp, the following types of wicks are more auspicious. Each type of wick has a special significance.
Cotton wick - Lighting a lamp using this wick will bring auspiciousness
Plantain Stem wicks - Will bestow with offspring
Lotus flower stem wicks - Will bestow all prosperity and blessings of Goddess Lakshmi.
Errukku Wicks - to remove debts and negativity