Maintenance of a printhead of a printer

A printer comprising:

• a printhead having a nozzle plate, the nozzle plate comprising, a first layer having at least one immiscible fluid chamber for retaining an immiscible fluid and a plurality of ejection fluid chambers for retaining an ejection fluid;
• a second layer having a plurality of ejection fluid nozzles in fluid communication with the plurality of ejection fluid chambers, an ejection fluid nozzle from the plurality of ejection fluid nozzles provided in fluid communication with an ejection fluid chamber from the plurality of ejection fluid chambers;
• an intermediate channel forming a passage between the first layer and the second layer, the intermediate channel being in fluid communication with the at least one immiscible fluid chamber;
• a base layer coupled to the first layer, the base layer having an immiscible fluid ejection mechanism to achieve ejection of the immiscible fluid from the at least one immiscible fluid chamber;
• and a control device coupled to the immiscible fluid ejection mechanism to regulate the immiscible fluid ejection mechanism to achieve the ejection of the immiscible fluid from the immiscible fluid chamber to convey the immiscible fluid towards at least one ejection fluid nozzle from the plurality of ejection fluid nozzles, the immiscible fluid ejection mechanism to form, within the intermediate channel, an ejection fluid-impermeable film of the immiscible fluid over the ejection fluid chamber in fluid communication with the at least one ejection fluid nozzle.