Calligraphy rice paper folding grids are generally works with a relatively small number of characters and relatively large characters, making it easier to fold. If there are too many characters, the grid lines will not be clear because the folding is thicker. It is recommended to calculate and draw with a ruler, pencil or willow charcoal. After writing, you can erase it with an eraser if it is not needed. It will look better even without erasing.
As a teacher majoring in calligraphy, I believe that there is no need to fold back the grid when writing. You can just stack a square grid. There will be restrictions on the grid.