Space is at a premium in my pocket bindery, and the smaller models of my Rota-Trim and board shear are limited in the size of materials they can cut. I needed to trim out consistent 4"x30" strips from a full 22x30 sheet of watercolor paper for the folded pages of a book project. As measuring, marking, and eye-ball cutting yields varied results, I set up a simple cutting jig as follows:
1. Make a bottom stop by clamping a straight edge to the worktable. [I aligned it to a grid line on my cutting mat]
2. Cut two spacers from bookboard scrap and mark their orientation. In my case, the 4" required less the 1 3/4' width of my cutting bar required [two] 2 1/4" spacers.
3. Position the paper against the bottom stop, place the spacers against the bottom stop, then position the cutting bar against the spacers and place a weight on the cutting bar to hold it in place. As my cutting bar is shorter than a full width of watercolor paper, I first made a 3/4 cut, then slid the cutting bar and spacers towards the uncut edge to complete the remaining cut.