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Trial of Water-Colour Paints

An instructive set of trials of water-colour paints was commenced in May, 1894, and continued for four years by a sub-committee of the Burlington Fine Arts Club. The results of these experiments have been embodied in three reports. Winsor and Newton's moist water-colours were used, flat washes on Whatman's 'not hot pressed' paper of the year 1888 being exposed to light in the windows of the billiard-room of the club. One of the sets so exposed was in an ordinary glazed frame, another set was enclosed in hermetically sealed glass tubes containing ordinary air; while a third set was contained in similar tubes, but the atmosphere present was maintained in a dry state by means of a reservoir of burnt lime which absorbed all or almost all traces of water in the pigments, the paper, and the mount. The final comparisons were made with parallel sets which had been kept in absolute darkness. We give here, in tabular form, the condition of the paints at the end of the fourth year of exposure: reference must be made to the original reports for information as to the results of six months' and of thirteen months' exposure to sunshine.

Results Of Exposure For Four Years, From May 25, 1894, To May 25, 1898

(Original depth = 10)

Pigment

Set in Dry Air

Set in Moist Air

Set in Frame

Aureolin ....

No change.

Faded to 9.

No change.

Gamboge ....

Faded to 1.

Faded to 1.

Faded to 1.

Indian yellow

Gone.

Faded to 1.

Faded to 1.

Cadmium yellow

Deeper orange.

No change.

No change.

Vermilion ....

Greyish.

Greyish.

Greyish.

Crimson lake ....

Faded to 0.5.

Gone.

Gone.

Rose madder ....

Faded to 8.5.

Faded to 8.0 and purplish.

Faded to 8.5 and purplish.

Indian red ....

No change.

No change.

No change.

Madder carmine

Faded to 9.

Darker, more purplish.

Darker, more purplish.

Pigment

Set in Dry Air

Set in Moist Air

Set in Frame

Madder brown

Faded to 9.

Faded to 6, purple gone.

Faded to 8, purple gone.

Madder purple

Faded to 8.

Faded to 4.

Faded to 5.

Prussian blue ....

No change.

Faded to 1.

Faded to 85.

French blue ....

No change.

No change.

No change.

Indigo .... ....

No change.

Faded to 1, greenish grey.

Faded to 1, greenish grey.

Vandyke brown

Faded to 2, less yellow.

Faded to 1.

Faded to 1.

Sepia .... ....

Faded to 8.

Faded to 1.

Faded to 4.

Indigo with Indian red ....

No change.

Indigo gone.

Indigo gone.

The most striking results of these trials was the complete stability of Prussian Blue and of Indigo when exposed in air kept dry. The further remark may be made that moist air, that is, ordinary air containing moisture and confined in a sealed tube, inflicts more injury upon alterable pigments than ordinary air enclosed in a frame which does admit of some amount of ventilation occurring. There is no difficulty in so constructing a frame as to introduce a water-absorbing substance which may be renewed from time to time. Thus we shall be able to employ with confidence in water-colour painting madder brown, madder purple, Prussian blue, indigo and sepia - five pigments which under ordinary conditions of exposure to sunshine suffer serious changes. But no method has yet been devised by means of which we may safely use gamboge, Indian yellow, vermilion, crimson lake and Vandyke brown, although it must be stated that instances have been recorded in which vermilion as a water-colour has stood very severe exposure-tests, especially when white of egg has been mixed with it.


Last Update: 2011-01-23