Step 2: Bleed through
I have been using this copy of the Greek New Testament over the last 45 years. It contains markings from a wide variety of pens. This page shows markings from two pens that bled through the paper. Look to the right of the numeral 8. You can see "NB" (Nota Bene = pay close attention, Important!) in reverse from the other side of the paper. It was made with a fine point fountain pen, but that pen put too much ink onto the paper for marking Bible paper, and it bled through. Notice the red "5-6" below the "NB." For a while I used cheap red ballpoint pens for Bible marking. Within a few years the ink took on an oily look and bled through the paper, even though it looked fine for a while. I quit buying those cheap red pens. The red ballpoint in the Introduction is a pretty good pen, much better than the cheap ones I used years ago.