matter of opinion, a
A question on which people hold different views, as in I rather like that design, but really, it's a matter of opinion, or The quality of that new stock issue is a matter of opinion. This expression was first recorded in 1843.
Is It “Opinion Of,” “Opinion On,” Or “Opinion About”?What do you believe the difference is? Opinion of values an opinion, opinion on emphasizes the topic of an opinion, and opinion about emphasizes the opinion itself. All three are fair ways to use the word opinion, but there are some major differences in how each phrase is typically used. Opinion Of Opinion of is the most common phrase among the three. Your opinion of …
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.