Which one to use in printing: CW or CCW rotated vertical text?

Question

What are your opinions, which of the following text are easier to read?

1. CCW text in one row
2. CW text in one row
3. CCW text in two rows
4. CW text in two rows

And what if the writing is on a vertical flag? (for example on the wall of a building?) Would you prefer 5. CCW flag or 6. CW flag? (Above the head of the reader, for example starting 4 m high.)

I found a detailed study on Comparing reading speed for horizontal and vertical English text. Their results are the following on the basis of 2 experiments on 10 and 24 young native English speakers (adults). It would be interresting to study this topic with much more people (for example here).

They have tested the following text types:

Can you add any additional resources regarding CW vs CCW rotated vertical text in print design? Or do you have any "ultimate solution" answer to my question?

My opinions:

• On a book 2. CW text seems more natural and easier to read (and it is commonly accepted, although I've found a different book on the shelf)
• But in case of a flag I would prefer 5. CCW text since you have to look up to the flag, and I suppose you start readign on the bottom.

I found these QA-s on stackexchange but all are about web UI-s, not print design:

• Usability of vertical text
• Is clockwise or counter-clockwise rotated text easier to read?

Answer 1

Counter-clockwise. It is easier (scientifically proven as far as I am concerned) that it is easier for people to correctly orientate CCW text than CW.

Additional resources? Hows a Harvard Psycho-linguist? http://pinker.wjh.harvard.edu/articles/papers/Finke_Pinker_Farah.pdf

CW is even worse for multi-line, because us westerners are trained to read left to right, top to bottom. 2 or more lines CW violates these rules.

Answer 2

This is a very loaded question that will be strongly affected by a cultural bias.

As I mentioned on the issue you linked, there are competing standards in different parts of the world. In the US and Commonwealth countries, text on spines is oriented top-to-bottom (i.e., rotated clockwise), whereas in mainland European and Latin American countries, it's the opposite.

Each standard has some unique advantages:

1. In the top-to-bottom format, books laid on a table with their covers facing up have readable spines. This is particularly ideal when it comes to single books like coffee table books:

   

2. In the bottom-to-top format, a series of volumes remain in logical order whether stood vertically or laid horizontally, which makes a lot of sense in things like DVD racks or bookshelves:

   

There's no one right answer. For me—as an Australian—I'd always choose top-to-bottom vertical text, since that's the convention in my country. Breaking the convention comes at a higher cost than being "right" for one specific controlled scenario.

If I was publishing a book for distribution in Europe, I'd print the spine bottom-to-top for the same reason.