Printed matter, manufacturing method for printed matter, program, and printing apparatus

A manufacturing method for a printed matter for creating the printed matter, the manufacturing method comprising:

• creating the printed matter in which a plurality of ink layers overlap each other by ejecting ink onto a medium by a printing apparatus, wherein
• the printed matter includes:
• an image layer that is one of the ink layers in which an image to be observed from a predetermined observation-surface side is drawn with the ink;
• and
• a light transmission rate adjustment layer that is one of the ink layers formed on a side of the image layer that is opposite to the observation-surface side,
• the light transmission rate adjustment layer has a low-transmission region and a high-transmission region,
• a light transmission rate of the high-transmission region is higher than a light transmission rate of the low-transmission region, and
• the light transmission rate adjustment layer causes light to be transmitted through the printed matter such that a pattern corresponding to a shape of the high-transmission region is visually recognized by an observer observing the image layer from the observation-surface side, when irradiated with rear-surface light which is light with which the printed matter is irradiated from a side opposite to the observation-surface side, and
• causes light to be transmitted through the printed matter such that the pattern corresponding to the shape of the high-transmission region becomes inconspicuous when not irradiated with the rear-surface light.

A printing apparatus that performs printing, the printing apparatus comprising:

• an ejection head that ejects ink;
• and
• a control unit that controls an operation of the ejection head, wherein
• the control unit controls the operation of the ejection head to cause the ejection head to create a printed matter in which a plurality of ink layers overlap each other,
• the printed matter includes:
• an image layer that is one of the ink layers in which an image to be observed from a predetermined observation-surface side is drawn with the ink;
• and
• a light transmission rate adjustment layer that is one of the ink layers formed on a side of the image layer that is opposite to the observation-surface side,
• the light transmission rate adjustment layer has a low-transmission region and a high-transmission region,
• a light transmission rate of the high-transmission region is higher than a light transmission rate of the low-transmission region, and
• the light transmission rate adjustment layer causes light to be transmitted through the printed matter such that a pattern corresponding to a shape of the high-transmission region is visually recognized by an observer observing the image layer from the observation-surface side, when irradiated with rear-surface light which is light with which the printed matter is irradiated from a side opposite to the observation-surface side, and
• causes light to be transmitted through the printed matter such that the pattern corresponding to the shape of the high-transmission region becomes inconspicuous when not irradiated with the rear-surface light.