DTF white ink contains titanium dioxide which will separate after being stationary for more than eighteen hours. So DTF white ink need a daily shake. And regular printing is the best way of maintenance actually.
Our vacuum white ink bag is designed to protect head for there is no air bubble during shaking ink bag.
There are processes that can permanently damage the nozzle if the print head have been over-heated during printing process. This is why we should do a print head-cleaning cycle to remove the air bubble in ink tube after installing a new cartridge.