Final answer:
The artistic technique used in creating the Bandolier Bag by the Lenape tribe from c. 1850 CE was Beadwork on leather.
Step-by-step explanation:
The artistic technique used in creating the Bandolier Bag by the Lenape tribe from c. 1850 CE was Beadwork on leather. The bag was initially made from native-tanned leather as the base and then decorated with porcupine quills. However, later versions of the bag, influenced by trade with the Europeans, used glass beads instead of quills.