Line Width
This is nothing in the Laws of the Game that indicates line width so you are free to interprate as you wish. What you do need to take into account is how the lines are used within the Laws which might give you something to consider.
For example, the ball is "in touch" when the ball carrier stands on or over the touch line. Over the touch line with a very narrow line marking is obvious but what about "on" the touch line. If the line is wide standing on the line is much easier to see. I feel that anything between 2" and 4" is a good line, much smaller and they become less useful to match officials and any bigger they become an area on the field not a line.
|