HP Deskjet 6840 Color Inkjet Printer - Manual (Page 113)

6. Remove the replacement print cartridge from its packaging and carefully
remove the pink, plastic tape.
1. Remove the pink tape only
Caution: Do not touch the print cartridge ink nozzles or copper contacts.
Touching these parts will result in clogs, ink failure, and bad electrical
connections. Do not remove the copper strips. They are required
electrical contacts.
1. Do not touch the copper strips
7. Hold the print cartridge so that the copper strips are on the bottom and facing
toward the printer, and then slide the print cartridge into the cradle as shown.
HP Deskjet 6800 series printer User's Guide
113