Reply To: Accessing a font's kerning table/values?

Andy,
Many years ago (mid ’60s to mid ’70s) I worked for HMH Publishing (Playboy Magazine) in Production and as such bought a lot of typesetting from different typesetting companies, all resting with the dinosaurs. One firm’s work stood above all the rest. We used them to set headlines and display type for that reason. I inquired as to why they were so much better than the rest. The answer was that the rest of the craftsmen relied on kerning a pair of characters but their craftsmen looked at the characters before and after the offending pair and kerned or letterspaced those pairs as well to achieve the more uniform gray.
The purpose of kerning to this day is to achieve a pleasing overall color. This is the justification for the paragraph composing engine in InDesign over the former single line composer. The paragraph composer is constantly reevaluating the “color” of the paragraph to blend tight lines with loose lines.
To see whether I might be too keen on the optical kerning method in InDesign, I set some words that contained an awkward pair of characters with both optical and metrics. When I added different characters before or after the pair, the optical method adjusted the spacing throughout the new word while metrics only treated the pair for which there was a value in the kern table. By my observation the optical method was far better overall color and thus readability.
My conclusion is that you have to consider what your goal is and at what expense. Both engines run in the background and should not make any difference in time.
Best regards