The picture is a very common occurrence in archaeological collections. I would place money on the fact that they used a fine pointed sharpie and they was definitely no overcoat! In archaeology, we have to label so much material that printing and applying tags would take far longer than applying the labels by pen and ink. We use B-72 but have a thinner bottom coat and thicker top coat to keep from smearing the ink. We have also found that the Millenium Zig pens have a “tougher” ink than the Pigma pens do. I learned using crow quill pens and having a disposable pen is fantastic technology!