Any character without its own key required manually inserting the appropriate mat in the line which was a time consuming process. You’ll notice if you look clos

Any character without its own key required manually inserting the appropriate mat in the line which was a time consuming process. You’ll notice if you look closely that there are keys for fi fo ffi and ffl as well. f was the Achilles heel of the Linotype machine. Because of the way it worked, it wasn’t possible for one character to overlap the next so even with the f ligatures, it was possible to get ugly combinations like fifty fifes. One 1920s design had f-ligatures available for most combinations of f+a letter but was incapable of being used to typeset Kafka or Afghanistan.