When buying violin strings I am often confused about what end the string has. For the E string it usually says ball-end or loop end, but often the other strings do not mention the end explicitely. Can I assume that ball-end is implicit?
It depends on the type of strings.
For steel or synthetic core, the three lower strings are always ball end, and you can get three different types of ends for the E: ball end, loop end, or removable ball end (take the ball out and you get a loop end).
But gut strings are available in either ball end or loop end for all strings - some manufacturers offer only one, some give you a choice.