Shine a Light Under the Paper Cutter to See Exactly Where the Blade Cuts
Paper cutters are precision paper cutting tools with one minor drawback: you can’t always see where the blade is cutting. For some models, this can be corrected by shining a light under the paper.
As Reddit user VolcanoHoliday points out in the photos above, by shining a light under the paper, you can see exactly where the edge of the paper cutter ends and therefore where the blade cuts. Unfortunately, this only works with large paper cutters like this one, where the blade goes down and cuts along the edge. Smaller paper knives like this one, where the smaller blade slides over the paper, don’t have a drop edge beyond which you can direct light. However, if you need to regularly use one of these large paper cutters, setting the light can help you be more accurate.
See the exact cut line on any paper cutter. Will never come back! | Reddit