Step 19: Place ink cartridge in mini-pen, and you're done!
Once you are happy with your whistle, you can turn it back into a mini-pen for storage. Slide the now-shortened ink cartridge back into the pen. If d...
Step 18: Cut ink cartridge
Measure and cut the ink cartridge at 2 1/8 inches from the part which begins the straight portion. The ink doesn't generally come out, but if you leave it sitting somewhere on an angle, or touch the ends with your fingers, it can get a little messy.