Masky Blade: Retractable blade tape cutter

Masky Blade is a compact tape cutter built for fast, clean cuts on almost any type of tape. It expands on the original Masky, which was built for masking tape, by adding broader tape compatibility and multiple blade options. 

Assembly Instructions & Usage:

Usage with various tapes:

Blade compatibility:

• There are 2 blade options: standard 61 mm utility blades (trapezoid) and 40 mm single edge scraper blades (rectangle). Tape roll compatibility ranges from narrow electrical tape up to wide packing tape. Left and right handed versions are available so you can match the orientation you naturally use when holding the roll.

• Blade recommendations:
  • Utility blade: I find the Milwaukee 3x utility blades are inexpensive and sharp. I DO NOT recommend the Stanley ones - they are not very sharp.
  • Serrated uitility blade: A serrated utility blade is even better in my testing!
  • Single edge razor blade: I find the Amazon Basics single edge razor blades to be incredibly inexpensive and sharp. 

Left-hold and Right-hold versions:

• Left hold (typically for right-handed folks): Masky and the tape roll is held with your left hand and tape operated with right hand. All images on this post are of the left-hold version.
• Right hold (typically for left-handed folks): Masky and the tape roll is held with your right hand and tape operated with left hand.

Print notes:

• No supports or brim needed. However, it is possible for the rail mechanism on the main body to warp off the plate, and then the slider will not work. Make sure your bed is super clean, or use glue stick, to prevent this warping.
• Recommend 4 walls and 40 percent infill. Increasing the wall count can cause print defects on the rail assembly.
• PETG is ideal for the spring. The rest is fine in PLA.

Assembly notes:

• These written instructions are supplemental to the video. Just watch the video (at the top) and you should be good.
• There are only 3 parts - the main body, the slider, and the spring. They should require zero cleanup - they are designed to work straight off the printer.

• Insert the blade into the slider by feeding the cutting edge in first (there are tiny notches to retain it), then press down. The blade should be completely flush with the surface of the inside of the slider (nothing sticking out - or it will conflict with the sliding mechanism).

  
  Incorrectly vs correctly installed blade. Make sure the edge is installed correctly. There is a tiny notch that retains the edge of the blade.

• While carefully holding the blade against the slider, slide the slider onto the main body. It should travel freely with no resistance. If it binds, look for small print defects on the rails (e.g. bulged corners or loose filament) and clean up or reprint. Consider adding a small amount of lube on the sliding mechanism.

• It's possible for the rail to warp off the build plate (especially for filaments prone to warping and build plates that are not perfectly clean). This issue will make everything extremely tight.

  
  In such situations you can use small file to straighten out the inside edge of the rail and resolve the print issue. Or re-print with a clean build-plate, glue stick, and/or a filament less prone to warping.
  
   

• Insert the spring with the point upward and rotate counter-clockwise until it drops into place. The slider will then be spring loaded and retained. Lefties: cross your eyes and rotate the lefty version clockwise.

  Insert with point of spring towards the top

  Use a screwdriver or your finger to turn the spring counter-clockwise

  You should here it click down into place. It should look exactly like this.

Holding Masky (a PSA):

• These written instructions are supplemental to the video. Just watch the video (at the top) and you should be good.
• If this thing fields weird or awkward, you MIGHT be holding it wrong.
  (cue Steve Jobs voice: "You're holding it wrong.")

Put your index finger on the “trigger” and the rest of your fingers (or at least your middle finger for the small rolls) on the inside of the tape roll.	In a “pinching” style motion, press your thumb on the slider. The grip should feel natural.
After you pull the tape over the blade, pull the tape to the left or right or twist (rather than literally straight down flat on top of the blade), to perform a slicing motion across the blade. You are slicing the tape, not chopping the tape.

Support :

If you want to buy me a beer or just reach out, you can find me here. Whether it’s feedback or just a nod of appreciation, I’m always happy to hear from people. But let’s be real - the most effective form of communication is cold, hard cash (or beer).

Changelog:

• 2026-01-25 – V1 Initial release.
• 2026-02-07 - V2 
  • Now supports the Customize tool!!! Customize to your exact needs in a desktop browser.

  • Changed model geometry to include 6-degree blade angle to improve cutting for those who pull the tape straight down over the blade instead of slicing the tape from one edge to the other. All model geometry is now larger as a result. Slicing motion still works notably better, if you are capable. If you want the original sizes with straight blades that do straight cuts, they are in the downloads section (V1).

Boost MeIf you scroll past this boost button and don't click it, does the button even really exist?

Disclaimer: The blades for this tool are extremely sharp. Make sure you understand how the blade retraction works, keep an eye on the blade at all times while operating, and keep your hands clear. Ensure any cutting motion involves your hands moving away from the tool, not towards the tool. Not for use by children. Store in a safe location.