An example system includes an advancement mechanism to drive print media into a stacking region, a movable media guide arrangement and a controller. The movable media guide arrangement includes a pair of opposing media guides to receive opposing edges of a print medium therein and a translation mechanism to move the opposing media guides between at least two positions, the at least two positions including a deployed position and a retracted position. The controller is to actuate the translation mechanism to move the opposing media guides into the deployed position when the advancement mechanism transports a print medium into the stacking region and to actuate the translation mechanism to move the opposing media guides to the retracted position to release the print medium.