After the success of the communist revolution in 1949, the People’s Republic of China decided to use horizontal writing. All newspapers in China changed from vertical to horizontal alignment on January 1, 1956.
The traditional writing direction for Chinese is from top to bottom (vertical) and from right to left.
The picture above is the comparison between traditional and PRC standard student exercise books. The exercise book on the left is traditionally printed while the one on the right is printed with the standard of Mainland China. There are spaces between columns for the traditionally printed as the writing direction is from top to bottom and from right to left. As for the PRC standard one, the spaces are between rows as the writing direction is from left to right horizontally.
Due to differences in writing direction, traditionally printed book has binding on the right, that means you have to flip to the right when you read, while PRC standard book has binding on the left.
Advantages of Vertical Writing
Vertical stroke is one of the two most important components of Chinese character, another one is horizontal stroke. The vertical stroke is made by pressing the index finger down on writing instrument. According to this book, as the stroke order of Chinese character is also from top to bottom, vertical writing creates vertical axis and helps the downward movement of index finger. Hence, vertical writing makes Chinese writing straighter and smoother.
Due to the great influence of Mainland China, many Chinese books that are published outside of Mainland China follow the PRC standard. However, Chinese books that are on the subject of Chinese languages are usually printed traditionally, if they are published out of Mainland China.
I think more Chinese books should be printed traditionally. The forceful change of writing direction (and Chinese character) is the by-product of the era in which people believed that the cleareance of old Chinese culture could lead to a better China. The purpose of the change is to alienate and disconnet people from the tradition. In the end, time proves that the disconnection with tradition is wrong and people are now striving to connect with tradition again. Also, I am not happy with the treatment of vertical writing with nowadays technology. To this date, we still can’t type Chinese character vertically on any web browsers.
As you can see, it is harder to mix English into vertically written Chinese.