The Tetragrammatron LSD Blotter

full image detail Tetragrammaton -this print depicts a four-way hit that was originally issued circa 1977. Iso series*. Mark's remarks: These pre-perfed beauties may be the first sigil on blotter. Magical! * Iso Series, when a perfed print has been "dipped" there remains on the paper a chemical residue that appears as a brownish stain after the paper has aged and been exposed to daylight. We use the term Iso Series to distinguish between these chemically stained examples from McCloud's collection and the items that have never been "dipped". The Iso Series prints feature this staining and the effect it has had on the inks and pulp of the paper in high, photographic detail - stunning.

via http://blotterbarn.com/grammaton.html