Except for experimental purposes, never go above about Quality 95
Using Quality 100 will produce a file two or three times as large as Quality 95, but of hardly any better quality.
Quality 100 is a mathematical limit rather than a useful setting, it is not a percentage....
If you see a file made with Quality 100, it's a pretty sure sign that the maker didn't know what he/she was doing.
Source > http://www.faqs.org/faqs/jpeg-faq/part1/section-5.html
Using Quality 100 will produce a file two or three times as large as Quality 95, but of hardly any better quality.
Quality 100 is a mathematical limit rather than a useful setting, it is not a percentage....
If you see a file made with Quality 100, it's a pretty sure sign that the maker didn't know what he/she was doing.
Source > http://www.faqs.org/faqs/jpeg-faq/part1/section-5.html
Patrice