Hidai Nankoku’s Work (1964) is an immense 3.5 x 4.6 metre ink artwork. Hidai painted Work on a large piece of paper holding the brush upright like in regular calligraphy practice. However, his lines go against the standard movement and direction of calligraphic strokes and have no specific meaning, rejecting conventional practices of calligraphy.

Below, M+ Paper Conservator Jo-Fan Huang explains how she and her team dealt with this large work.

This is a paper-based, calligraphic work, but on a monumental scale. It's the product of a performance—maybe that explains why, when we received the work, it was folded up to the size of A2 paper. It was only when we opened it that we realised how big it was.

When Work was created, it was laid flat on the ground. The work is composed of ten sheets of paper put together and is quite thin, especially for an artwork of such large dimensions. If displayed upright, the thickness of the paper simply cannot sustain its own weight. Due to various handling and storage conditions, the work’s edges and folds also had an extensive amount of tears, breaks, and surface abrasion. That's why we had to come up with a treatment plan and determine the best way to display it.

The first thing we had to do was to make sure that the creases were reduced and improve the storage conditions. The work had been repeatedly folded and unfolded along the same lines, so there were a lot of local distortions and buckling. Being folded was not the best storage condition for this artwork, so we opened it up and rehoused it in a rolled condition. Then we dealt with the problem of unstable, cracking ink and the adhesion between the ink and the paper. Finally, we reinforced the paper support from the back.

To our surprise, we found a few bare footprints directly on top of the ink. At first we thought they were the artist’s footprints, from when he was making the work. However, there's video footage of this work being created, and, in the video, Hidai is wearing socks. We didn't want to risk removing the footprints if they were part of the artwork, so the curator, Lesley Ma, actually contacted the artist’s estate to ask. They confirmed that the footprints were not meant to be there and that we could remove them.

However, there are, in fact, some hairs from brushes left on the surface, held in place by a few dots of ink. We left those as is because they are part of the artwork and the performance through which it was created.

Because the creation of the work was documented, and we know how it was made, we suspected that the ink may have had a different composition than normal calligraphic ink, which is composed of soot with animal glue. The ink is surprisingly matte and has a certain thickness to it. It also seems that when the ink dried, one or more of these added materials contracted, causing cracking. We received an informative note from the estate confirming this: the ink is composed of soot, animal glue, and wheat starch paste. This provides important context to complete the story of this artwork.

Because the artwork is so large, when we worked on it, we had to roll it out gradually, and attend to it section by section. We had to tailor-make tools and tables to match its size. For example, we used different materials we could find to make the table’s edges rounded, so that we didn’t accidentally create more creases. We unrolled it using a tube, and then moved it to another tube as we unrolled it. We only worked on about eighty centimetres at a time.

To reduce the creases and flatten the work overall, we applied humidification, followed by stretch drying. This involves making the work moist, so that it expands, and then drying it out, which causes it to contract, while stretching it to keep it in place by fixing the edges to a support—in our case, the floor.

To humidify the work, we gently introduced moisture through a pre-moistened sheet of blotting paper and placed it on top of a barrier film, which lies on top of the artwork. This is then covered with plastic for about an hour. During that time, the work expands evenly. We designed special hinges to keep the work in place that could be used for both stretch drying and installation.

Once we removed the plastic, we had to scramble. Paper works dry very quickly and almost immediately start to contract. Because the artwork is so large, we had to move around the perimeter very quickly and adhere it to the floor. I had four colleagues help me. While we spent an entire day preparing for humidification, setting out the blotter, and covering everything, the actual stretching treatment was done in just fifteen minutes. It was exciting and fun, but I’m not looking forward to doing it again anytime soon!

After we stretch dried it, some of the natural distortions from when the ink was first placed on the paper returned. However, it’s possible those natural distortions were there already, but we just didn't see them because there were so many folds. As a paper conservator, it’s transformations like this that I find the most interesting. We always want to return the work as closely as possible to the condition of when it was made with the least amount of treatment.

Paper works of all sizes have the same quality: a sensitivity to fluctuations in humidity. We wanted to create a backing board that enhanced the resilience of the work when displayed. To help with this, we teamed up with Hong Kong University Libraries (HKUL) Preservation Centre learned about the technique of karibari.

A karibari board is a tool developed by Japanese mounters of the scroll mounting tradition. It's a wooden lattice core with up to eleven layers of paper on both sides. It's also called a drying board, because it allows the painting to dry on top of it.

The technique works because the papers gradually respond to moisture, enabling the painting attached to the board to expand with it. Sometimes, if old paper paintings dry too quickly, the force of the drying can actually tear the paper. Having so many layers and air pockets within the drying board helps slow down the drying process.

Although karibari boards are typically used only for drying, we would like to design a karibari-like backing to allow Work to respond to environmental fluctuations. In fact, there is actually a tradition in Japan that uses the karibari technique to display paintings. For example, the technique is used for folding screens, which often had paintings on them. However, karibari is not usually used on something of this size. Traditional paintings were around two by two metres large at the most.

It’s fascinating to me how, at M+, we often need to look back at traditional techniques in order to solve our very contemporary problems. We're always trying to dive deep into our professional experience to bring life to artworks in new ways.