An image formation apparatus includes: an image former that forms an image on a recording medium delivered along a predetermined delivery path and outputs the recording medium; a first hardware processor that judges whether or not the recording medium is an envelope; a second hardware processor that acquires a basis weight of the recording medium; a third hardware processor that determines control for when an image is formed on the recording medium on the basis of a judgment result from the first hardware processor and a basis weight acquired by the second hardware processor; and a fourth hardware processor that controls operation of the image former on the basis of a determination result from the third hardware processor.