Possibly as a money-saving exercise, these comics followed the Newsprint Series (see link below), as being printed in Digest-Sized.
It reprints the cover and the following story from DC Comics' Batman 134 (1960):
"The Rainbow Creature"
Also reprinted is this story from DC Comics' Batman 135 (1960):
"The Return of the Second Batman and Robin Team"
Also reprinted is this story from DC Comics' Batman 134 (1960):
"The Deadly Dummy"
Also reprinted is this story from DC Comics' Batman 100 (1956):
32 pages, glossy colour cover, black-and-white newsprint interior pages.
These titles were printed in a smaller size (187x131mm) compared to the original DC Comics title.
The printing reproduction from the original was very good quality.
Here is the cover of issue 21 and DC Comics' Original cover:
House ads for All-Star Western and Western Picture Library:
Mimosa Detective Comics Series
Mimosa Batman Newsprint Series