This section is from the book "The Boy Mechanic Vol. 2 1000 Things for Boys to Do", by Popular Mechanics Co.. Also available from Amazon: The Boy Mechanic, Vol2: 1000 Things for Boys to Do.
White lead, thick shellac, and pastes that are used occasionally may be preserved by laying a piece of leather over the exposed surface. When these materials are kept in cans, cut A piece of leather from the upper of a heavy boot of such A size that it will drop freely into the container. Form a handle on the leather disk by driving a nail through its center from the under side. Press the disk down smoothly over the surface of the contents and a thin film of oil Will soon form over the disk, effectually excluding the air. A loose cover is placed over the container, to keep out dust. - Contributed by Luther McKnight, Colorado City, Col.