Is there a neat word or phrase that summarizes the opposite of "one size fits all"? "One size does not fit all" is not an option. What am looking for is something that means "different sizes for anybody, for every occasion etc.".
This may be venturing away from English usage and into slogans, but maybe you could write "Our Sizes Fit All"? Realistically, it might be best to specify which sizes instead of groping for a single generic word to say "various sizes," although that phrase might work.
You could call it "sized" clothing, however it's much more common to use the word in a combination: an average-sized insect, an awkwardly sized package.