A display processing apparatus (11; 11A) comprising: a receiving unit (200K; 201K) configured to receive display information indicating whether gloss-control plane image data is displayed and whether clear plane image data is displayed, the gloss-control plane image data specifying a type of a surface effect to be applied to a recording medium and a glossy area to which the surface effect is to be applied, the gloss-control plane image data indicating a color of the glossy area when being displayed, the clear plane image data specifying a transparent image to be formed on the recording medium and indicating a color of the transparent image when being displayed; a generating unit (200H; 201H) configured to generate a synthetic image by synthesizing color plane image data indicating a color image and one of the gloss-control plane image data and the clear plane image data that is specified to be displayed by the display information; an operating unit configured to receive operation instructions issued by a user; a display unit; and a display control unit (200J; 201J) configured to make a control that displays the synthetic image on the display unit; characterized in that: the display unit is configured to display an input screen; wherein the input screen includes a display color setting field used for setting a display color that is a color of the transparent image when being displayed and a transparency setting field used for setting transparency of the transparent image when being displayed. a receiving unit (200K; 201K) configured to receive display information indicating whether gloss-control plane image data is displayed and whether clear plane image data is displayed, the gloss-control plane image data specifying a type of a surface effect to be applied to a recording medium and a glossy area to which the surface effect is to be applied, the gloss-control plane image data indicating a color of the glossy area when being displayed, the clear plane image data specifying a transparent image to be formed on the recording medium and indicating a color of the transparent image when being displayed; a generating unit (200H; 201H) configured to generate a synthetic image by synthesizing color plane image data indicating a color image and one of the gloss-control plane image data and the clear plane image data that is specified to be displayed by the display information; an operating unit configured to receive operation instructions issued by a user; a display unit; and a display control unit (200J; 201J) configured to make a control that displays the synthetic image on the display unit; characterized in that: the display unit is configured to display an input screen; wherein the input screen includes a display color setting field used for setting a display color that is a color of the transparent image when being displayed and a transparency setting field used for setting transparency of the transparent image when being displayed. the display unit is configured to display an input screen; wherein the input screen includes a display color setting field used for setting a display color that is a color of the transparent image when being displayed and a transparency setting field used for setting transparency of the transparent image when being displayed.