Unlike milling machines, cutting plotters do not have a z-axis that can be variably controlled in height. They only know the states "Move without cutting" ("Pen Up") or "Cut" ("Pen Down").

The correct setting of the blade holder and the pressure is important for accurate cutting. As a rule, the protrusion length of the drag knife is adjusted by turning a knurl at the rear. This moves the knife with its rear bearing longitudinally. A GRAPHTEC CB09-U holder is shown schematically here. Other plotters have similar mechanisms.

Another principle is a plastic cap mounted at the front, which moves backwards or forwards on a thread by twisting. The blade itself is then fixed axially.

The end of the blade holder should sit flat on the film, so that the film is pressed against the cutting bar or the table and it cannot bulge in front of the blade.

Professional tip: If you frequently cut different materials and need different blades or just different settings, it can be useful to have several blade holders with the appropriate settings available to simply replace the entire blade holder.