28th Feb 2024

Conservation Framing

What is conservation framing?
The conservation of art and heritage items falls into two main groups – remedial conservation and preventative conservation.

Conservation picture framing could be included in the category of preventative conservation. It involves the use of materials and methods that prevent or lessen the likelihood of future deterioration or damage and improve the long term stability of the works of art we are asked to frame. For example, light damage can cause significant loss of colour and induce brittleness in the medium itself – these effects are cumulative and difficult to detect over time. Fortunately, modern glazing that reduces ultra-violet light damage is available. We encourage clients to consider this option when discussing their framing choices with our staff.

Remedial conservation is the treatment of objects and artworks to rectify damage and restore artworks and objects to the original condition or intent of the artist. This work should only be undertaken by trained conservators who specialise in different mediums. At City Art Depot, if remedial work is to be considered, we refer clients to conservators recognised by the New Zealand Conservators of Cultural Materials. The conservators are guided by an established Code of Ethics: https://www.nzccm.org.nz/

Similarly, you may notice discolouration or other changes on some of your framed artworks at home. This damage can be caused by standard quality matboards and framing techniques – we have listed some of these here.

What are conservation framing methods?
City Art Depot uses museum quality materials and techniques to assist with the long-term preservation of your artwork. These include chemically stable 100% cotton fibre matboards and backing boards. Artworks are attached to these with Japanese mulberry paper hinges adhered with archival adhesives – these are designed to break under stress, such as during a fall, so preventing damage to the artwork itself. We seal the back of the frame with a dust cover to provide an additional layer of protection.

At each step of the framing process we take the utmost care with the piece being framed.

Why does conservation framing cost more?
Higher quality materials are more expensive and the methods more time-consuming. We believe the preservation of an artwork for the future is worth this extra expense. If the work you want framed is easily replaceable and not of great value to you, standard boards will do the job for the short term, but to protect your art work for the long term it should be encapsulated in fully archival boards before it is put into the frame. 

What is mulberry paper
Mulberry paper is made from the inner bark of the mulberry plant, widely cultivated in Japan. We use this with starch glue to hinge works on paper. Mulberry paper is strong under constant pressure but will tear under a sudden stress, i.e. if your frame is dropped or falls from the wall, unlike other adhesive tapes which would tear the artwork.

What’s wrong with standard matboards?
Paper used to be made from cotton – pure cellulose, no lignin, no acid. Now it is made mainly from timber. Timber is rich not only in cellulose (wood pulp) but also in lignin (found in the cell wall of the plant). It is the presence of lignin that makes commercial paper and boards so detrimental to works of art. Used as a backing or matting board in the framing process, such materials – be it paper, cardboard or MDF (medium density fibreboard) — are responsible over time for the hazy brown or yellow stains found on artworks or seen in the cut matboard edge. This is acid-burn, caused as the lignin breaks down and the acid migrates from the card or board to the artwork (MDF also contains formaldehyde which can off-gas and cause further damage).

Can I press my artwork against the glass?
Air space within the frame from either a window mat or spacer is important as water vapour within the sealed confines of a frame can condense on the glass and facilitate the growth of mould. Mildew evaporates in contact with air. If the work is in direct contact with the glass, it can be damaged by mould or become water stained. The air space also allows works on paper to expand and contract with changes in heat and humidity. If pressed to the glass, the artwork will scrape against the glazing and damage the surface. Fragile paper artwork mediums such as paint and pastel can also stick or transfer to the glass, becoming irreparably damaged.

Why isn’t my artwork flat?
Works on paper naturally expand and contract with changes in temperature and humidity. This causes the paper to ripple, undulate or “throw waves”. Different mediums applied to the paper can also cause movement, pulling the paper in places, this is particularly evident in some watercolour works.

Can my artwork be glued flat?
A work of art should never be completely adhered to a backing board. As works on paper expand and contract at a different rate to the board they are glued to, they can tear. As above poor quality backing boards and adhesives can also cause acid damage. Because backing boards (like the artwork) move with changes in humidity and temperature, you can end up with a warped artwork. At City Art Depot we use mulberry paper hinges to secure works on paper to the backing board. This allows for the natural movement of the paper while still holding the piece in place. These hinges can be removed by an experienced picture framer or conservator. Other adhesive tapes such as double sided tape, gummed tape and linen tapes shouldn’t be used in contact with the artwork as these yellow over time and sellotapes also go brittle and fail over time.

There are occasions when City Art Depot mounts photographs and reproduceable prints to rigid aluminium backing boards to prevent the buckling of modern photographic paper.

At City Art Depot we make education the first step in our preventative framing commitment. We are happy to discuss the various strengths and weaknesses of different framing options and explain how preventive methods and materials in the framing process can avoid such damage in the long term.

For further information please also see https://www.icom-cc.org/en/terminology-for-conservation and https://natlib.govt.nz/collections/caring-for-your-collections/caring-for-collections-guides/agents-of-deterioration