Shown here is the reverse side of a map drawn on parchment. At some point, the map has been fixed to a non-archival backing which, if left in place, may adversely affect its preservation. The backing is made from a stiff, 2mm cardboard which has yellowed over time, indicating the presence of acid. The difference in thickness between the parchment and backing has caused the sheet to curl and the resulting creases have attracted dirt due to being slightly raised. A dry treatment technique is appropriate to remove the bulk of the backing. Using a scalpel and other tools, the backing can be gradually scraped away either entirely or, as is more often the case, down to a thin skin. Great care is taken to ensure the document isn't damaged whilst conducting this method of mechanical removal. Following this, a carefully considered aqueous treatment such as humidification, soaking, or applying specialist chemicals (solvents, enzymes etc.) can be used to separate the final layer of backing.

B is for… #BackingRemoval

Non-archival backings can be harmful to documents. Using a scalpel and other tools, backings can be reduced to a thin skin and entirely removed with an aqueous treatment, so long as the media and substrate can withstand moisture.

#KAconservationAtoZ