Okey,

I have made some experiments to see the Impact mark.
1. Water was not visible
2. powder from kitchen was white and not very easy to see
3. Pro did not have tape and my tape was too hard. (The one builders use to protect areas - "white paper".) It needs to be softer.

I also taped a red arrow (30 cm long) on top of my 5 wood. ( Idea was to "see" the path of the swing. (Makes a tale for the clubhead) This almost worked. Arrow just would have needed to be plastique - or stiff - not to swiggle during swinging.

Thanks for all your input. Best thing about trying to see the impact mark has been that it has motivated me to look at the ball. I think I am hitting it better even though the project is not finnished yet:-)

Hannu
Jyväskylä,
Finland