Making skeleton leaves was a Victorian pastime that amused and absorbed bored housewives. Used in elaborate decorations, the leaves would be stripped to the veins using a technique known as maceration. This essentially involved soaking the leaves to soften them and allow the veins to reveal themselves.
The process called for flawless, mature leaves, which were placed in a container and covered with rain water. The container was then kept outside in the sunshine, and topped up with more water as needed. After two weeks or so, the flesh of the leaves would deteriorate and become pulpy, allowing for its removal with a soft brush.
Free of flesh, the skeleton leaf would be floated in diluted bleach and then dried in a warm place. The leaves remained relatively malleable, making them ideal for use in floral decorations. The maceration process has been adapted and perfected since the Victorian era; here is a guide.