Non-water soluble coatings, such as cellulose nitrate, found on mid to late 20th century architectural linens, bubbled in areas where water was trapped. Damage was apparent in all test samples but seemed most severe in vacuum freeze-drying processes.
Groupings of polyester-sleeved items were placed within sample boxes to see if they could be successfully vacuum-freeze dried. Would the vacuum process sublimate water out of openings in the sleeves? Would water be effectively removed from encapsulations where corners were clipped? Would water be removed from an ultrasonic or heat welded item?