There is provided a technology that enables reduction of an amount of data to be processed in testing a printed image printed on a printing medium. A printing apparatus includes a printing unit, a camera, and an image-data output unit. The printing unit is capable of printing plural categories of test patterns on the printing medium. The camera captures an image of a test pattern printed on the printing medium, and outputs acquired image data to the image-data output unit. The image-data output unit reduces an amount of data of the image data output from the camera, in accordance with the category of the test pattern, and outputs acquired image data to a test apparatus.

An example method is described in which a property is measured associated with air flowing through a print gap between a print head and a printing substrate, the print head to eject a print fluid on the printing substrate; an ejection of print fluid is adjusted from the print head based on the measured property.