Ink jet system

An ink jet system comprising:

• a recording device on which a head unit that ejects ink is mounted, the recording device performing recording on a recording medium;
• a processing device connected to the recording device and performing a data process for causing the recording device to perform recording;
• and
• a server connectable to either the recording device or the processing device, wherein
• either the recording device or the processing device includes
• a receiver that receives a control parameter from the server,
• a controller that controls an ejection operation for ejecting ink from the head unit based on the control parameter,
• a display unit that displays an evaluation input window having a function that user can perform evaluation on a first evaluation item and second evaluation item individually, the first evaluation item being to evaluate the control parameter, and the second evaluation item being to evaluate the control parameter and to differ from the first evaluation item, and
• a reception unit that receives an evaluation result by the user via the evaluation input window after the ejection operation.