she uses an ink called "skytex".
next: there are some spanish guys, who even print on icarex:
i saw a lot of revs and other kites with paintings.
most of them were beautiful, depending on the skill of the artist.
you should start to paint on white icarex, because it is difficult to "guess" the final color, if you add your painting on
a colored fabric. get some pieces of icarex to test first.
even with "permanent markers" you can draw very nice things on a sail.
in germany we can buy "refill-bottles" for permanent markers.
you can applicate this with a brush or whatever you want.
should be available in the US, too.
and, maybe best for calligraphics.
have look at shops, that offer paint for airbrushing.
they have paint, speciallized for fabrics.
it is really not a problem! just give it a try!
- Scott_of_melnsct likes this