Tape on Stones

Trying to find video of someone using masking tape on stones to find sweet spot for sharpening.
I had seen it on this forum but cant find it now

Try this
WEPS - how to mount and sharpen a ffg blade: http://youtu.be/2T0wQDHKMR0

That’s it. Thanks

I use blue painters tape since I have it for taping up the knife. I have used a pencil before too.