Shopping, things to do, not to forget, just make a little note and stick it in the paper clip which can be screwed to a wall or attached to the fridge with double sided adhesive foam tape or some small magnets. This system is often seen in restaurants to put the notes for running orders. Place two or more next to each other in case you need more space. This clip is 20 cm wide. If it just does not fit on your printer bed, rotate it 45 degrees along the Z-axis.
In case the gap is too wide for your paper, just glue a piece of paper to the back side.

To be printed with the slot down. If necessary, use brim.