Because the texture of ordinary rice paper (especially raw rice paper) is too soft and thin.
If you want to make a foundation, the easiest way is to paint it yourself.
But there are two other ways,
Is to choose a piece of rice paper more than two meters long, tough and thick.
Cut it to the right size and mount it in multiple layers to increase the thickness.
May be able to withstand the printer (? )
Second, you can use hard calligraphy and painting cardboard, or mount rice paper on cardboard.
But the specifications of cardboard are generally not too big.