Scanned detailed comments for a paper review Sometimes I find my self reviewing papers with authors who are not very capable English writers. I am a non-native speaker myself, and I know how difficult it can be to proof-read a paper in English, in particular if you don't have access to any native English speaker. If the scientific content of the paper is otherwise good, I therefore try to do what I can to correct grammar, poorly constructed sentences, spelling mistakes etc.
It often results in very long referee reports, which take ages for me to type. I was wondering if it would be proper form to simply scan a version annotated by hand, and attach it to the referee report? If you received such a thing, would you be grateful for the time spent, or would you consider it lazy that I did not type in all the suggestions in a proper report?
I think it really comes down to the editor. You should first ask the editor of the journal if there is any issue and then think if your handwriting is clear enough. Hoewver, please keep in mind that scanned copies cannot be copy - pasted. You could return a pdf or Word version of the paper with annotated comments, either on the side or baloons (Adobe Acrobat and Adobe Reader allow for that and I find it very useful when finalising a draft). This sounds to me like a more convenient solution that a scanned copy.
I would like to stress that, despite your good intentions, the full responsibility of presentation and language falls on the authors, not the referee. A paper is not just about content but also sound presentation and communication of ideas.