Unusual finds in the library’s collections: paintings on pith ‘paper’

State Library’s Conservation team recently worked on an unusual collection item – an album of gouache paintings on pith ‘paper’. This beautiful album is currently on display in the Botanica paradiso display on show in the Australian Library of Art Showcase on Level 4 of the State Library of Queensland. This article details the conservation treatment carried out on the work, and answers the question “What is pith paper?

What is pith ‘Paper’?

Pith ‘paper’ is not actually paper at all, it's a very fragile slice of wood bark. It is made by cutting a thin sheet from the inner pith bark of the Tetrapanax papyrifer plant. Any pressure applied to the pith ‘paper’ will distort it’s soft, velvety surface. The spongy cells react to moisture and so when painted they create a sculptural embossed appearance.

With age, the sheets of pith can become brittle, so with every page turn of the 12 paintings in this 1840s pith ‘paper’ album in the State Library’s collection, the pages were slowly starting to shatter.

This image shows the many places where the pith ‘paper’ was split, torn, creased and folded. Many areas had been lost over the 180 years of turning pages in this book.

29367 Botanical Gouaches on Pith Paper Album ca. 1840. John Oxley Library, State Library of Queensland.

Each of the 12 shattered paintings in this album were mended through delicate conservation work. 

Left:  Before Conservation, punctures, dents. 208x magnification.

Right: After Conservation, punctures flattened Butterfly legs are visible again after conservation. 208x magnification.

In this image we can see the edges were torn sharply along cell walls.  Blue watercolour wash sits translucently on the surface of the cell walls.  Purple and black pigments fill the voids of the cells creating a striking opaque effect.  Red pigments applied thickly are raised from the surface in some areas.

Some of the white lines are hairs from the artist’s paintbrush. 208x magnification.

State Library’s conservators and collection custodians share the same aim when it comes to preserving our collections - to retain as much original material as possible; leave original items in a better state than we found them and allow collection items to be accessible by the public. In discussion with our Queensland Memory team, we planned a detailed treatment for this album, deciding to retain the book’s authentic construction (as opposed to a more ‘invasive’ action, such as rebinding).

Album pages with paintings and its silk ribbon boarders detached.

29367 Botanical Gouaches on Pith Paper Album ca. 1840. John Oxley Library, State Library of Queensland.

To that end, we started by detaching each painting and its silk ribbon borders from the album pages. Using capillary action, each page in the book was washed. The same treatment was applied to each of the paintings, and each of the ribbon borders.  Then each conserved painting was re-attached to its original page.

Album pages with paintings and its silk ribbon boarders re-attached.

9367 Botanical Gouaches on Pith Paper Album ca. 1840. John Oxley Library, State Library of Queensland.

We also decided to preserve the pigment transfer from the paintings to the opposite page. It shows evidence of the painting process.

 Conservator Jennifer Loubser with pith paintings on Karibari. Conserved September 2020.

To preserve the embossed texture of the painted surface, it is extremely important not to crush or distort the surface of these fragile artworks during treatment.  A karibari, Japanese drying board, was used as a technique for flattening.  Using “false margins”, only air was in contact with the artworks while they were tension dried and flattened during treatment. No pressure was applied to the fragile artworks and the open cellular structure of the pith paper didn’t collapse during the mending process.   

Karibari boards were made by the State Library conservation team with the generous support and funding from the Queensland Library Foundation. You can learn more about Karibari boards in our blog - The gift that keeps on giving: Generous progress since a karibari board workshop.

After conservation, the 12 paintings on pith ‘paper’ were re -attached with hinges made of Japanese paper to their silk ribbon borders. They were then attached with paper hinges back onto their respective album pages. 

29367 Botanical Gouaches on Pith Paper Album ca. 1840. John Oxley Library, State Library of Queensland.

In carrying out this conservation treatment, we were able to return the album almost to its original state. This album can now be handled and viewed once again; to be enjoyed by many future generations of Queenslanders.  

29367 Botanical Gouaches on Pith Paper Album ca. 1840 is now on display in the Australian Library of Art (ALA) Showcase on level 4 at the State Library.  A digital version of the album will be available online in the not-too-distant future.

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