I have acquired three paper cutters over the last 5 years. One was a little used large model with a cast steel slicer and a hard wood deck.
I have found myself using the cutter more and more for making styrene pieces. My go-to method in the past was to use a dedicated dial caliper with one of the jaw points sharpened. I could scribe a full length line by dragging the non-sharpened jaw along the styrene edge, with the other jaw leaving a nice line. Place an exacto knife point into the scribe, and place the metal straight edge up to the knife blade and an accurate cut was assured. I did have to make a cheat compensation from the measured to exact differences, which in my case 0.003".
Now I simply use the depth pointer on the dial caliper to extend the caliper from the cutting edge of the paper cutter and slide the styrene sheet to the blocking point of the depth gauge. Aligning the styrene to the square lines on the base platform keeps the squareness assured. The beauty of this is the measurements are exact!
Another beauty of this paper cutter is the nice, straight edges without any left behind relic items which need follow up attention. The accuracy I achieve is down to 0.001". I have cut up to 0.040" though I am concerned that perhaps thicker styrene may hasten the dulling of the steel blade.
I needed to make a scale 1/2 inch by 2 inch door track protector, which was 5 foot long, on a wooden box car. I needed to make 4 or more attempts to get the perfect cut, but I was super pleased with the results. With this small of a cut, I simply eyeballed the sizes and kept trying to get to where I was satisfied. For this door track piece, I sliced an Avery peel and stick address label. When finished with the slicing, I peeled off the backing and the tiny track strip went down with good adhesion. I am super pleased with the scale size and strength.
I am 68 years old and I am still learning and trying new ideas!