Washable Gray Marker
Make a crease visible for the goaltenders but as safe as possible for equipment rub off. 
 
This marker is a lighter thickness and uses 100% washable light gray color ink.
 
We are attacking the concerns of goalie equipment rub off from multiple angles --
1) 100% washable water based ink. 
2) Lighter ink release puts less marker ink the ice
3) Valve tip allows for more thickness when desired by depressing marker tip (see videos)
4) Light Gray ink-  Even in the worst ice conditions if goaltenders do not wipe off their pads the light gray ink blends in with puck marks = virtually impossible to see any rub off.