Annotating and proof-reading documents are common tasks. Digital annotation tools provide easily searchable annotations and facilitate sharing documents and remote collaboration with others. On the other hand, advantages of paper, such as creative freedom and intuitive use, can get lost when annotating digitally. There is a large amount of research indicating that paper outperforms digital annotation tools in task time, error recall and task load. However, most research in this field is rather old and does not take into consideration increasing screen resolution and performance, as well as better input techniques in modern devices. We present three user studies comparing different annotation media in the context of proof-reading tasks. We found that annotating on paper is still faster and less stressful than with a PC or tablet computer, but the difference is significantly smaller with a state-of-the-art device. We did not find a difference in error recall, but the used medium has a strong influence on how users annotate.