Pentel teacher s homework pen energel 0 7mm violet ink pentel bl117w v p many educational authorities now recommend that teachers no longer use red ink pens to mark students work because research shows that comments in red ink can be seen by students as discouraging upsetting harsh confrontational threatening like being shouted at and can even be responsible for weakening teacher student relations p p a much calmer colour like this violet energel pen from pentel provides the perf