Paper is indeed one of the mediums that could hold a stain of blood. I've seen some crime scenes with such, spatter patterns on newspaper, etc. Just as Amer Indians used brain matter for tanning, think of your typical cloth/leather/linens/paper/etc as those that typically stain. As far as a corrosive blood stain? Well, I guess its possible, but how does one determine that the corrosion is truly from blood vs moisture/salt air(maritime)/water,etc,etc. It would seem like the bloody blade would have had to have been put in a drawer literally still clotting for awhile for this result.
