You can use that and a digital camera. I've been doing that and found the 85% rule comparing actual length (from the widget or measuring by hand) to the shed. But, as I said, its a genral rule. Your corn might have a different %.
The BP seems to be closer, like 96% because when she sheds, it rolls up kinda like a doughnut. It is because shen she sheds, she makes laps around the inside of her hide. It doesn't really catch on anything and get pulled like the corn's.
Here is a snake shed video I put together if you haven't seen it in action. Sorry guys and gals but a BP shedding is kinda boring so this is one of my corns. http://youtu.be/3vzE_f5TdiE
Ohh. Thanks for the link and info!
And Mike, I thought the shed would shrink down after the moisture was lost. Lol