Buffered vs Unbuffered

Buffered vs Unbuffered

What is the Difference? 

When choosing archival materials, you'll come across the terms ‘buffered’ and ‘unbuffered’. Knowing which is right for your items can make a difference to how well your treasures are protected. 

 

During the manufacturing process, some archival paper, card, board, and tissue materials have calcium carbonate added to them. This makes them a ‘buffered’ product. The added calcium carbonate creates an alkaline environment, with a pH of 7.0 or above. This alkaline environment helps to protect whatever is wrapped or stored inside from acid damage.  Using a ‘buffered’ product to store your treasures is a simple but effective safeguard; it works quietly in the background to slow the natural ageing process and keep your items in better condition for longer. 

 

When should I use buffered materials? 

 

Buffered enclosures (boxes, folders, tissue, envelopes) are the better choice for most items in storage. The buffering agent will help to neutralise acids and acid migration between objects.  

 

Items best stored in buffered materials are: 

 

  • Documents and paper items, maps, manuscripts, books, prints & drawings 

  • Film and most photographs (black & white prints, colour prints) 

  • Textiles and artefacts – cellulose based (plant based) items such as bark, cotton, linen, wood  

 

There are, however, some exceptions to using buffered materials for storage. 

 

When should I use unbuffered materials? 

 

The alkalinity in buffered enclosures, while beneficial for most items, can actually cause harm to certain sensitive materials. Dye transfer prints and cyanotypes, for example, are best kept in unbuffered enclosures, as both are sensitive to alkalinity. The same applies to animal-based materials such as silk, wool, leather, feathers, horsehair, animal specimens, and blueprints. These should either be stored in unbuffered enclosures or separated from any buffered materials by an unbuffered layer. The good news is that buffering agents don't transfer between materials, so a buffered box can still be used safely, provided the item is first wrapped in unbuffered tissue, paper, card, or polyester/polypropylene film. 

 

A Quick Guide: 

Use buffered materials for:    

                            

  • Paper Documents / Newspapers 

  • Photographs 

  • Ceramics, textiles & artefacts 

  • Plant specimens  

 

Use unbuffered materials for: 

 

  • Silk, wool, leather, parchment, feathers, horsehair, pearls 

  • Animal specimens 

  • Blueprints and cyanotypes photographs 

  • Albumen and dye transfer prints 

  • Protein-based materials 

  • Textiles with unknown dyes 

  • Mixed and unknown materials  

 

If you are unsure, unbuffered is the safest option for any object, and we always recommend you contact a trained conservator for advice.