100mm extrusion guide

I was trying to dial in my printer, so I watched the youtube vids and read some pages about extrusion.

While trying to mark my filament I fussed with rulers and tape measures, but my pathetic human form found I was shy of hands or dexterity.

The premise is simple, use a target line (at a known distance) and another line a bit further on so you know the overshoot.

Printing precision isn't important here, knowing the distances is the key. I like easy math, so I dialed my printer until t