Doesn't say anything on the guidance notes, so I assume one is free to use whatever ink one feels like (Pink maybe

).
I have given up writing with a pen since long (thanks to technology), so I just filled it electronically and took a printout. I must say this is the worst form I have ever seen designed (different fonts, different font sizes, somewhere bold and at some places regular ... my god

).
Payment page has an issue where it doesn't let you enter anything in a couple of boxes (in Payer / Card holder name). So I filled up the boxes that I could electronically, took a printout and then used a black pen to write the missing alphabets manually to complete my name
Hope they won't have a problem with what I have done

. Else, there go the 315 quids down the drain.
regards