While all enclosures deteriorate over time, those made from acidic paper or board can damage the collections they are meant to protect relatively quickly. Many enclosures can cause damage because they are the wrong size and do not provide proper support. In addition, fasteners, attachments, and inserts (e.g., paper clips, pins, rubber bands, poor-quality bookmarks, Post-it Notes, etc.) can stain and tear paper collections.
Poor-quality enclosures and older preservation-quality enclosures can be tested with a pH pen, available from conservation suppliers, to determine whether they are acidic or alkaline.
Take a few moments to look at the pictures below. What problem do you see in each?
: What is wrong with each picture?