Illuminated fish skin bag

How to conserve a fish skin bag

By Sophie Louise Rowe, Organics Conservator

Publication date: 20 October 2020

As we prepare to open the Citi exhibition Arctic: culture and climate, Organics Conservator Sophie Louise Rowe talks us through how she went about conserving two bags made of an unusual material.

How to conserve a fish skin bag

In preparation for the upcoming Citi exhibition Arctic: culture and climate, conservators in the Organics conservation lab have come across an array of unexpected and incredible materials used by Arctic Peoples to make everyday objects. Windproof and waterproof translucent parkas made from the intestines of bearded seals, tiny bags intricately sewn from the feet of ducks and harpoon floats used in hunting, made from the bladders of walruses and stomachs of seals, all feature in the new exhibition.

The objects – and the materials used to make them – are testimony to the amazing ingenuity of the communities in the circumpolar regions. The people who live in these harsh environments have a respectful relationship with the resources and animals around them. The drive to ensure no part of a slaughtered animal is wasted means that parts of animals that we would usually discard have been beautifully and expertly crafted into the most wonderful materials and objects.

Two objects in particular have piqued the interest of conservators and visitors to the lab alike – two bags made, in the most part, from fish skin, or iqertiit in the Yup'ik language. Yup'ik is the name of the cultural group who produced the bags – they live in the western and southwestern regions of Alaska. The bags themselves, which are known as kellarvik or qemaggvik, meaning storage bag or container, were collected in 1890 (so are likely to have been made before then) and come from southwestern Alaska.

Although perhaps surprising, fish skin is something that was, and still is, quite commonly used in communities across the Circumpolar North. A flexible and waterproof material, it can be used for a variety of different purposes. Aside from bags, the British Museum collection contains examples of shoes, mittens and sewing kits all made from fish skin!

The process of skin preparation can vary from maker to maker but the general principle is that after the meat of the fish (most often king or silver salmon) is removed for eating, the skin is scraped to remove excess flesh and fat. The skins are then soaked in a vat of urine. The ammonia in urine is good at removing fats and oils and preventing decay. Skins would then be rinsed and could be rubbed with fats and/or oils such as fish oil or animal brains, both to soften and to tan the skins. After drying, the skins have to be physically manipulated to make them softer and more flexible. The more the skins are worked, the softer they become. Sometimes the skins are also smoked or dried outside in winter, which freeze-dries them, making the skin paler.

I was so interested in fish skin material and how it is made, that last May I travelled to Sweden to learn how to make fish leather with expert tanner Lotta Rahme. Although the process itself can be a little smelly at times, the resulting skins do not smell at all, and can be beautifully soft and strong.

Woman softening oil-tanned fish skin at a table set up outside in residential area
Conservator Sophie Louise Rowe softening oil-tanned fish skin in Sweden by rubbing and manipulating the skin over a blunt metal tool.

The bags themselves would have been used for different things. The larger (really quite huge!) bag would have been ideal for storing things such as clothes, furs and skins inside the home. The skin of this bag is very soft and supple, almost floppy, and very thin, similar in thickness to linen cloth. In contrast, the smaller bag is likely to have been used outside to pick berries or carry water or food. In comparison to the large bag, the smaller is very rigid, as if it has got wet during use outside. It is also a bit sticky which hints at the fact that oils have soaked into the surface, either to make the bag more waterproof, or as a result of something oily stored in it. It's wonderful when you can see and feel the history and use of the objects in front of you.

On both bags, the scaly sides of the skins are mostly facing outwards. However, where there are bleached (white) or dyed skins (red), the skins are turned inwards so that the scales are on the inside of the bag and the softer smoother skin underneath is exposed. What is great is that it is still possible to see the form of the fish, as there are areas where the fin has been removed and the resulting small hole delicately stitched closed. Most of the seam stitching on the bags is done with sinew – a strong fibre made from tendons or ligaments, possibly of beluga whale or caribou (reindeer) – but you can also see white decorative stitching on both bags, which is believed to be caribou throat hair.

Close up of the original area of fish fin on a fish skin bag
Detail of one of the bags where the fin of the fish has been removed and the hole carefully stitched closed.

On the smaller bag, there are also small strips of white decoration. This is likely to be bleached seal throat, or oesophagus, often used to decorate objects. In wintertime, the oesophagi of seals would be cut from the stomach, inflated and left to freeze-dry outside in the cold, which would turn them very white. These freeze-dried oesophagi are called nerutet in Yup'ik.

Close up of fish skin bag showing decoration of caribou chin hair stitching and oesophagus strip
The fine white decorative stitching on the smaller kellarvik, or storage bag, which is likely to be caribou throat hair. The reddish-brown material is fish skin turned inwards so the scales are facing inside the bag. It has been coloured either by rubbing a pigment like ochre, or by dyeing using something like Alder bark. The strip of cream material is likely to be freeze-dried oesophagus (nerutet).

For the conservation treatment, it was important to figure out what was needed to ensure the safe display and handling of the bags. Overall, the larger bag was in worse condition and because the bag itself is quite large, it was sagging under its own weight, causing it to become misshapen and creased. Creasing is a problem with materials like leather, as it causes the fibres to become damaged, creating an area of weakness that is likely to tear. A number of tears were already spotted on the bag, which were causing it to become even more misshapen and likely to get bigger if not addressed.

Fish skin bag with decorative detail
The larger bag, or kellarvik, before treatment.
Close up of a large tear on the bigger fish skin bag
Close-up of a large tear in the bigger bag.

In order to repair these tears, and to re-shape and remove creasing from the bag, it needed to be placed in a higher humidity environment. Increasing the humidity around an object allows us to gently and carefully relax the leather and make it temporarily more flexible. In order to do this, a large sealed chamber was created and moisture was introduced to slowly raise the ambient humidity. After a day relaxing in the chamber, the bag was much more flexible and it could be gently re-shaped.

Fish skin bag during humidification treatment sealed in plastic
The sealed environment used to raise the humidity around the large bag.
Large tear on fish skin bag in process of repair with Japanese tissue tabs and magnet circled
Repairs at an early stage. Small tabs of Japanese tissue are used to bring edges temporarily into alignment. Small round magnets also help to hold everything in place.

At this point the edges of the tears could begin to be brought back together. This started by using little temporary sticky tabs, made of Japanese tissue. These function almost like sutures or stitches, to bring the broken skin back together from the front, checking that everything was in good alignment. The bag was then supported on its side which allowed access to the inside to carry out a supportive repair.

Conservator with her head in a fish bag making repairs
The bag turned on its side and conservator Sophie working inside to repair tears.

It is sometimes quite surreal when you find your day at work involves spending hours with your head in the depths of a giant fish-skin bag! But being able to work on the inside of the bag meant that supportive patches of Japanese tissue could be introduced as a backing along the tears. Japanese tissue is commonly used to repair tears in the conservation lab – its long fibres mean that it is actually quite strong for a material that appears so thin, but it is also flexible and sympathetic to materials such as leather. The way in which the backing was applied makes it easily reversible if it ever needs to be removed in the future.

Japanese tissue used to repair fish skin bag
Japanese tissue backing. The tissue can be coloured with paints to a sympathetic colour so that it is not visible. This is then adhered to the inside of the back using a thin film of heat-activated adhesive and very delicate and precise heated spatula.
Japanese tissue backing on inside of bag, with circle on image to mark location
Japanese tissue backing in place inside the bag which can only be seen faintly.

Once the backing was in place, the temporary tabs on the front of the bag could be carefully removed so that the repair was not visible. A number or repairs were carried out in this way, and each was carefully documented so that future staff are aware of the more modern intervention on the bag. Once all tears were stabilised, the large bag was gently re-shaped and filled with custom-made pads and foam supports. These allow the bag to be fully supported during display, as well as in long-term storage.

Close up of a large tear on the bigger fish skin bag before treatment
Tear before treatment.
Close up of a large tear on the bigger fish skin bag after treatment
Tear after treatment.
Image of entire large fish skin bag after conservation
The large bag after treatment.

The smaller bag was in better condition, but needed a few creases to be removed, and it had some tears which needed support. Initially, we used Japanese tissue to support the tears in the same manner as the larger bag. However, curators and exhibition designers wanted to illuminate the smaller bag in way that showed off the amazing translucent qualities of the fish skin. But passing light through the bag highlighted the opaque tissue repairs! Something more transparent as a backing material was required…

Close up showing Japanese tissue repairs on the top rim of the bag, three arrows on image pointing to areas
The first Japanese tissue repairs on the top rim of the bag.
Light highlighting visible repairs with circle on image marking location at top of bag
The first repairs are visible as shadows at the top of the bag when light was shone though the bag.

In the end, a repair was carried out using a material called 'Goldbeaters skin', which is actually processed intestine, traditionally from an Ox. This might sound like an odd choice, but Goldbeaters skin is often used to repair parchment, so is a tried and tested method. The real benefit is that the material is transparent and very thin, so light passes through it well and repairs appear almost invisible.

Hand in blue medical glove holding up piece of goldbeater skin
Goldbeaters skin being used to repair the smaller fish skin bag. You can see how transparent it is.
Circle showing location of goldbeaters skin repair
Goldbeaters skin repair adhered in place on the reverse of a tear.

Although not as strong as Japanese tissue, which is made of cellulose fibres, Goldbeaters skin was good for the minor repairs required on the smaller bag and, once in place, you couldn't notice the repair at all.

Fish skin bag illuminated from behind to show translucency
The bag, illuminated from within, with repairs now invisible.

Both bags are now looking much happier and are ready for display in the exhibition.

Fish skin bag on display next to other objects including parka
One of the bags on display in the Citi exhibition Arctic: culture and climate.

It was real joy and a privilege to work with these objects – and to learn so much about the people who made them. Much of the information in this blog on materials, processing, and use of objects has come from videos shared on the Smithsonian Arctic Studies Center's YouTube Channel where detailed explanations and demos from Alaskan fish skin makers and artists Audrey Armstrong, Coral Chernoff and Marlene Nielsen were invaluable. Discussions with Alaska Native community members and artists recorded on the Smithsonian Native Collections 'Sharing Knowledge' website and from the book Yuungnaqpiallerput: The Way We Genuinely Live, Masters of Yup'ik Survival and Science by Ann Fienup-Riordan were also vital resources. These are all collaborations between museums and Alaska Native community representatives and makers. Many thanks are offered to those who shared this knowledge.

Illuminated fish skin on display in exhibition
One of the bags on display in the Citi exhibition Arctic: culture and climate.

Read more blogs from the Citi exhibition Arctic: culture and climate, which ran from 20 October 2020 to 21 February 2021. 

Lead supporter Citi

Supported by

Julie and Stephen Fitzgerald

AKO Foundation

Arctic exhibition book cover showing title and prow of boat in icy water

Buy your copy of the beautifully illustrated book accompanying the exhibition, named one of the books of the year by the Times.