chemical bleaching

Fine Art Conservation: Gloucester Harbour, Watercolour Painting by J. M. Barnsley

19th century watercolour painting by J. M. Barnsley, before and after conservation treatment.

19th century watercolour painting by J. M. Barnsley, before and after conservation treatment.

Sometimes bad things happen to good art! This elegant watercolour painting by Canadian artist J. M. Barnsley had suffered water damage in a flooded basement, causing a large disfiguring stain across most of the image. 

19th century watercolour painting by J. M. Barnsley, suffering water and mould stains.

19th century watercolour painting by J. M. Barnsley, suffering water and mould stains.

Luckily, recent stains are often easier to treat than old stains, and when the owners brought it to Book and Paper Conservation Services, we were able to help. 

The process was multi-fold. First, the acidic pulp board backer on the watercolour was removed. This step was painstaking and time-consuming, but necessary before any cleaning could be undertaken. The brown colouring and acidity of the pulp board had leached into the painting when it was exposed to water, causing the staining in the image; it had also caused the paper overall to yellow and deteriorate. Backer boards like this are very common on 19th century watercolours, and this is why we always recommend they be removed as a preservation measure for any work of art on paper. 

Removing the acidic pulp board backer from the watercolour painting.

Removing the acidic pulp board backer from the watercolour painting.

Verso of the watercolour after backing removal. The stain is evident, as is the adhesive residue of the backer board. 

Verso of the watercolour after backing removal. The stain is evident, as is the adhesive residue of the backer board. 

Once the painting was free of the backer board, it underwent aqueous cleaning in deionized water; this treated not only the overall yellowing of the paper but also began the process of loosening the dark brown staining in the image. After several rinses, the watercolour was air dried, and the results evaluated. Washing had brightened paper tone and significantly reduced the hard brown water stain.

The watercolour during aqueous cleaning. The stain is loosening as water molecules penetrate the paper fibres. 

The watercolour during aqueous cleaning. The stain is loosening as water molecules penetrate the paper fibres. 

Yellow discolouration removed by the first immersion cleaning.

Yellow discolouration removed by the first immersion cleaning.

After washing, before chemical bleaching. The paper tone is brighter, the staining is reduced.

After washing, before chemical bleaching. The paper tone is brighter, the staining is reduced.

After extensive testing to determine the sensitivity of the pigments and potential reaction of the stain, the final step was to locally apply a chemical bleach to further treat the discolouration. Only solutions that have been tested and approved by conservation scientists are used for chemical bleaching treatments, and only in very controlled applications; the treatment must not leave any trace amounts of chemical, or cause any further damage to the materials. In this case, a very low percentage of a reducing agent was used, and the paper was then rinsed multiple times to remove all chemical residue.

Testing local application of chemical bleach. 

Testing local application of chemical bleach. 

The bleaching treatment further reduced the stain, to the point that it is nearly eliminated. Light losses to the watercolour pigment in areas of mould damage were inpainted to unify the image. The scene can now be appreciated without distraction, and the paper tone is brighter, allowing the colours to appear as the artist intended. 

After conservation treatment, the staining is barely visible, the paper tone is brighter and the image can once more be appreciated without distraction.

After conservation treatment, the staining is barely visible, the paper tone is brighter and the image can once more be appreciated without distraction.

An unexpected revelation after treatment was the title of the painting, Gloucester Harbour, handwritten in graphite on the lower left corner of the verso. 

The title of the painting,  Gloucester Harbour , revealed on the verso.

The title of the painting, Gloucester Harbour, revealed on the verso.

The clients selected a new framing scheme for the artwork, and our conservation framing included Japanese tissue hinges adhered with reversible wheat starch paste, acid-free backer and mat board, and GroGlass ARTGLASS 99, offering 99% UV protection. The watercolour painting by J. M. Barnsley is once more looking its best, and is properly preserved for the future. The owners have it displayed in their home once again, and one day will pass it down in their family.  

Conservation framing completes the project with acid-free materials and UV filtering glass.

Conservation framing completes the project with acid-free materials and UV filtering glass.

If you have an artwork that has been damaged by flooding or another catastrophe, don't hesitate to contact us to discuss restoration options. You may think there's little hope to reverse the damage, but it never hurts to get a professional opinion; we're not miracle workers, but quite often conservation treatment can dramatically improve a damaged work of art.

Check out our portfolio of treatments, or contact us today.

Art Conservation: David Milne Watercolours

David Milne watercolour painting - art conservation

David Milne is one of Canada's most iconic artists, and his sparse, evocative style is seen to great advantage in his watercolour paintings. But as with any art on paper, Milne's works are very susceptible to damage and deterioration. Book and Paper Conservation Services recently restored three David Milne watercolours for the Art Gallery of Windsor

Big Moose , David Milne, watercolour on paper, before conservation treatment. Staining and mat burn disfigure the image.

Big Moose, David Milne, watercolour on paper, before conservation treatment. Staining and mat burn disfigure the image.

The three works on paper are part of a bequest given to the Gallery by the Estate of Leslie Stibinger, and had not previously been displayed. Moisture and poor storage conditions before acquisition by the gallery had resulted in mould and mildew stains in the paper, as well as mat burn around the perimeter of all three artworks.

Weed Mines , David Milne, watercolour on paper; before conservation, dramatic staining in the upper right quadrant disfigures the work. 

Weed Mines, David Milne, watercolour on paper; before conservation, dramatic staining in the upper right quadrant disfigures the work. 

Last Snow of Winter , David Milne, watercolour on paper, before conservation treatment. Mat burn around the perimeter was the worst damage to this piece. 

Last Snow of Winter, David Milne, watercolour on paper, before conservation treatment. Mat burn around the perimeter was the worst damage to this piece. 

Verso of  Last Snow of Winter , showing tape and adhesive residue, before conservation treatment.

Verso of Last Snow of Winter, showing tape and adhesive residue, before conservation treatment.

The watercolours came to Book and Paper Conservation Services for conservation treatment in the summer of 2017, in advance of the exhibition 'Blazes Along the Trail': Exploring David Milne’s Imaginative Vision, running October 21, 2017 – January 28, 2018. The Gallery was eager to include these three works in the show, but wished to have them restored to their best condition before display. 

The stains in white areas of the paper disfigured the images and distracted from the viewers' appreciation of the composition. The mat burn around the perimeters hindered the works from being displayed to their outermost edges, and the remains of acidic tape and adhesive on the reverse of the works were causing long-term deterioration. These issues were addressed during the restoration of the works.

Testing treatment of mat burn on  Weed Mines , David Milne.

Testing treatment of mat burn on Weed Mines, David Milne.

Stain reduction on  Weed Mines , David Milne.

Stain reduction on Weed Mines, David Milne.

Removal of tape and adhesive residue from verso of artwork.

Removal of tape and adhesive residue from verso of artwork.

Cleaning and stain reduction in progress on  Weed Mines , David Milne, watercolour on paper.

Cleaning and stain reduction in progress on Weed Mines, David Milne, watercolour on paper.

After extensive testing of the media, paper and stains, a treatment protocol was proposed that included surface cleaning, local stain reduction using chemical bleach, and mechanical removal of the adhesive tape. Over the course of several weeks, the treatments were painstakingly executed to restore the works to Milne's original vision.

Weed Mines , David Milne, watercolour on paper; stained area before and after conservation.

Weed Mines, David Milne, watercolour on paper; stained area before and after conservation.

Big Moose , David Milne; staining before and after conservation treatment.

Big Moose, David Milne; staining before and after conservation treatment.

The three watercolours have been stabilized and preserved, and now that they are back in the care of the Art Gallery of Windsor, they will remain safe for future generations to enjoy. These works, along with a number of other paintings and prints by Milne, are on display in the exhibition 'Blazes Along the Trail': Exploring David Milne’s Imaginative Vision until January 28, 2018. 

Weed Mines , David Milne, watercolour on paper; after conservation treatment. The staining across upper area of image has been dramatically reduced, restoring the integrity of the artwork.

Weed Mines, David Milne, watercolour on paper; after conservation treatment. The staining across upper area of image has been dramatically reduced, restoring the integrity of the artwork.

Big Moose , David Milne, watercolour on paper; conservation treatment has reduced stains so they no longer detract from the image.

Big Moose, David Milne, watercolour on paper; conservation treatment has reduced stains so they no longer detract from the image.

If you would like to read more about Milne's art, the AGW's collection, and the conservation treatment of these watercolours, you can access a free e-publication produced by the Gallery to accompany the exhibition, available on their website. Book and Paper Conservation Services was pleased to contribute an essay on our work conserving the Milne watercolours.

Last Snow of Winter , David Milne, watercolour on paper; after conservation, mat burn has been eliminated so the image can be viewed out to the perimeter. 

Last Snow of Winter, David Milne, watercolour on paper; after conservation, mat burn has been eliminated so the image can be viewed out to the perimeter. 

We are happy to work with both public institutions and private collectors to preserve important cultural objects for the future. View our fine art conservation portfolio to see other projects completed at the studio, and contact us anytime to enquire about restoration of works on paper in your own collection.

Restoration of Natural History Prints

These natural history prints were originally illustrations in a book, published in 1835. The steel engravings show shell and fossil specimens in exquisite detail, and are printed on thin, delicate paper.  

The four prints came to the studio in very poor condition. They had suffered water damage causing multiple stains, as well as mould growth and surface dirt, and were badly creased. 

Before treatment, set of four steel engravings, 1835

Before treatment, set of four steel engravings, 1835

Not all damaged items can be restored back to a pristine state, and this set is a perfect example. The dark stains were very set in the prints, the damage having occurred long ago, and the paper was thin and fragile. However, while conservation treatment may not always be able to restore a piece completely, it can produce dramatic improvement. 

Dry cleaning to remove surface dirt.

Dry cleaning to remove surface dirt.

First, the prints were dry cleaned to remove surface dirt and loose debris. Next, they were washed and light bleached in RO water. This process removed much of the acidity and discolouration from the prints, and brightened the paper tone overall.

After washing, showing the discolouration in the wash water.

After washing, showing the discolouration in the wash water.

Then, a chemical bleach was applied locally to further reduce the stains and tidelines. Finally the prints were rinsed and deacidified to finish the process. 

Spot bleaching through suction to reduce local stains.

Spot bleaching through suction to reduce local stains.

After treatment, the set of 4 prints is much improved. The paper tone is brighter and the stains are no longer dramatically disfiguring. The prints will never be new again, but aesthetically the set is much more acceptable now, and once properly matted and framed, will be suitable for display. Most importantly, the paper has been stabilized by the removal of dirt and acidity, and will remain in good condition for many years to come. 

After treatment, the prints are brighter, the stains reduced, and the paper stabilized.

After treatment, the prints are brighter, the stains reduced, and the paper stabilized.