Recently I started to seriously read digital manga in Japanese by utilizing their free-reading (立ち読み: read while standing) feature for some first chapters. Then I realized that some serieses use furigana on all kanji, and the rest only on some difficult/rare kanji.
Furigana on all kanji
Furigana on some kanji
So, who decides the usage of furigana in a manga? Is it the author's preference, or is it decided by the publisher?
Note: in this case, it's about furigana used for standard reading, not on its artistic usage/alternative reading/pun.