The Uniball Signo RT Gel mini Hack

Step 4 Check the modified Uniball Signo Cartridge

Here you see the nicely sliced Uniball cartridge, ready for insertion into the G2 mini pen body. If you want to be non-wasteful, you can keep the G2 mini cartridges for backups, or use clear tape to adhere the chunk of Uniball cartridge you've sliced off to the top of the G2 mini cartridge, and use this in a standard G2 pen. The G2 plus clipped cartridge combo doesn't work in empty Uniball Signo pen bodies, because of the G2's nib.