A basic guide to impressioning
A basic guide to impressioning that you may find useful to introduce the topic.
http://www.outsideinlocktools.co.uk/A%20Basic%20Guide%20to%20Impressioning%20V3%20by%20Simon%20Barber.pdf
http://www.outsideinlocktools.co.uk/A%20Basic%20Guide%20to%20Impressioning%20V3%20by%20Simon%20Barber.pdf