IMHO...It could well be that those pens work for you...but...considering the outlay....a Winsor & Newton Series 7 brush number 0 or 00 will not only work just for that one small application but also for a myriad of other painterly requirements 👍....with a brush you can knock back the colour/tone of your desired "print " to fit in with your overall paint scheme....it could be that a pen ,albeit very fine,will only give you a solid black that could change the perspective/overpower your chosen palette.......just my $0.002 😉