PIGMA Micron ultra fine point Bible pen by Sakura is perfect for notes and underlining. Ultra fine .20mm tip for precise marking; will not smear, fade, or bleed through. Archival; suitable for acid free environments. Also works well for papercrafts, journals, and other crafts. Black ink.
I can't bring myself to mark in most of my Bibles, but I ordered this pen in blue ink, as I have one small Bible in which I may decide to mark some favorite passages. I haven't actually written on the Bible pages yet, but I did try the pen on other paper. It marks in an ultra-fine line without any globs, much finer than a regular fine point pen, and I think it would be especially good for use in Bibles. Those who have a small handwriting size might also like it for regular writing.