I'm currently working on my Hybrid drawings (ballpoint pen, pencil & digital combined).Currently 'Clap 1' which has bee in progress for some time. It is a large drawing (usual 1016 x 1372 mm) and will take hours to complete. Even I struggle to work out which bit has been done by pencil and which bit has been done with wacom pen/ tablet (printed) which can make for even slower progress. I'm working from two different source 'inky hand prints' - one for the digital drawing part and one for the second pencil layer and it can be really tricky to tell which is which.
Clap 1 (detail): pencil, wacom pen/ tablet
The only real way to tell is to look at it at a certain angle when the 'sheen' of the pencil is more visible - particularly in the darker areas - so I'm constantly having to stop drawing and move around to get a better view of what/ where I'm drawing. Much easier of course when using a ballpoint pen.