A while back, Johnson Levels played host to the explain-all show How It’s Made. The resulting five-minute overview demystifies the making of a time-tested measuring tool –- the level.
They do a great job breaking down the production process for a laminated birch level. Of course, the real trick is getting the vials right and getting them in the beam as accurately as possible.
Though they didn’t show it, I was curious to see if they glued up, cut, and sanded the beam on-site or had them prefabricated elsewhere. I suppose that part of the process isn’t very interesting to anyone but wood geeks, so I can see why it didn’t get any airtime.