Agreed that many don't have access to photocopiers, but if you do, it is the easiest and most accurate for young snakes. It's easy to miscount ventrals on small sheds, and they're only good if intact. Copier light is not a problem as it's very brief and you're shooting the belly. The nice thing about a copier is that you have a permanent record and you can write the number of each scale right on the paper.

Kelly