We cannot be sure as we do not read Chinese, but suspect these to be practice sheets from a student of Asian calligraphy. The same characters seem to be written over and over again and in some places the the handwriting has been stamped with a red chop. Most of the ink is black, although some has faded and a very few have some ink splotches where the student made and corrected an error.
Each sheet measures 9-3/4 by 5-1/4 inch. The handwriting is on one side only. However the ink has carried through to the other side.
These are a fortunate find as practice sheets are generally discarded. We're showing several sheets so that you might see the similarity and variance. Some are filled with writing, others have some empty space.