If in the process of printing I ended a black tank, can I put gray and continue printing?
Empty and clean thoroughly as per these instructions :
Upon starting a new print, the printer will warn you that the tank is registered with the wrong resin. You can override this warning and continue printing without any problem.
If you’re in the middle of the print and your cartridge is empty then you may still have enough resin in the tray to finish the print, you can continue printing without anything dispensing from the cartridge. You just need enough resin in the tray so that it covers the area that you are printing.
If you don’t have enough resin in the tray then you should not use a different type of resin, the printer will have been using settings designed for the first resin and each resin has different print settings so you risk print failure or poor quality by mixing resins or using resins with the wrong settings.