I wonder if this'll work...

Eventually, I will have to indicate where the jaw cut lines are on a clay vent figure sculpture. But how do I make sure the lines are parallel to each other and straight up and down? Well, this hacked tool might work.

I took two 90-degree-bent brackets and Krazy-glued them together. I measured the top and bottom to make sure the distances between them are the same (in this case, 2-inches apart). Then I Krazy-glued a small line level to the bottom of the brackets.

My plan is to make sure the line-level bubble indicates I'm holding it level, then I'll gently press the edges of the brackets into the clay.

For wider jaws, the brackets could be spaced and glued farther apart. Think it'll work?