Utility blade paper slicer by pearboyfrob on Thingiverse: https://www.thingiverse.com/thing:7310406

Summary:
I have a ton Dewalt utility blades, so all my slicers use them.  This is great for cutting wrapping paper cleanly, or opening vacuum- or heat-sealed bags.  I've even used it to open mail.Edit: note - So far I've printed on my Flashforge Adventurer 5M Pro with Flashforge HS PLA and Flashforge PLA Silk (both with default settings).  With the HS PLA, it may seem a bit tight at first, but once the parts fully cool to room temperature, the parts fit together great.  The Silk, because it tends to expand a lot, is still difficult to open - though not impossible.  Actually, I found it's pretty easy to open (even when tight) by carefully bending it in half slightly (does not need a lot).  May need to scale one of the parts up or down a tad to accommodate if printing in PLA Silk.