This picture is from:  Chippewa Valley Museum
When a deer was shot and killed, Ojibwe Indians would stretch the animal skin so it would be a large flat area to write or draw on. The writing utensils were made of sticks or other wood.  The paint was made from flower petal juices. The writings were used to tell stories.  The skins could be used for covering the entrance to a wigwam or for clothes.