Printing system including a pretreatment-head capping mechanism with dual-position operation

A printing apparatus comprising:

• a platen configured to convey, in a conveying direction, a printing medium to be subjected to a pretreatment for applying a pretreatment agent containing any one of an acid, a salt, and an acid and a salt before or after the platen is located at a set position;
• an ejection head having a nozzle surface provided with a nozzle and configured to perform an ejection process of ejecting a liquid from the nozzle onto the printing medium conveyed by the platen at a printing position that is located at a downstream position in the conveying direction with respect to the set position;
• a cap configured to cover the nozzle surface;
• and
• a cap switching mechanism configured to switch a position of the cap between a capping position where the nozzle surface is covered with the cap and an uncapping position where the nozzle surface and the cap are separated from each other,
• wherein the cap switching mechanism moves the cap to the uncapping position after a printing start instruction is received,
• wherein the cap is moved to the uncapping position during a period of time between an end of the pretreatment and a start of the ejection process.