Storing Oil Paintings
A walk through any great museum leaves you aided by the impression of the permanence and power of oil painting. Oil painting is considered the most natural and enduring of all painting media, with that said, it is worth taking good care of paintings too. The very first side bar has links through the Smithsonian Museum Conservation Institute to recommendations on care and storage of artworks, we advice you check these call at addition into the information below.
The information and knowledge below is approximately taking care of of storage: the change in colour of oil paintings in dark storage, that recovers when cut back into the light.
- Oil painters can amass a wide range of paintings. And we also are then up against the problem of where and how to store the artwork. Understanding the lessons through the 550 years of oil painting we understand that oil paintings age best in stable and moderate environments. This includes moderate temperatures and humidity, and a moderate number of light. The general recommendation through the Smithsonian is actually for dark storage, but oil paintings usually takes continuous light exposure, in fact light exposure is wonderful for the binder.
- Along with of a drying oil in a finished paint (linseed, safflower, walnut, and even alkyds) changes in response to your quantity of light. Light exposure bleaches oil, as well as in the dark, drying oils upsurge in color. It is important to realize that for the vast majority of paintings and also the the greater part of storage conditions these changes are imperceptible.
- Nevertheless, we made a decision to study and measure this phenomenon for ourselves: the change in the colour of oil in terms of light levels. Henry Levinson, who founded Permanent Pigments in 1933, had done a similar test, the results were published in the 1970’s. (1)
Change is the Rule
- The precise colour of an oil painting is continually changing in response to degrees of light. Robert Gamblin learned this several years ago when he had drawdowns regarding the whites we make on his office wall. Each month he would measure the color with your spectrophotometer, and then graph the outcomes. He had been in search of any meaningful change in color. Instead, he found the littlest up and down movements in the measurement of color. With time, Robert realized that the drawdowns were responding to the elements, the movements he saw were in response towards the quantity of sunshine coming through his window.
- The two charts below show the change in brightness in only one white oil color, Titanium White, over a year’s period, as the oil slightly changes color as a result towards the amount of light that it is receiving. What you see into the charts are simply the L* value (lightness, which goes from 1-100) in an L*a*b* system of color measurement.
- Studying the chart of improvement in lightness on a field of all values from 0-100, you can view there is very little change. In fact the alteration is imperceptible towards the eye. Nevertheless the photo spectrometer is incredibly sensitive and in looking at the chart below (detail of the chart to the right) you can view that there are alterations in the lightness of this white over the course of a year.
- Notice where the L* value dips? This is how it is cloudy for a few days before measurement, and where L* raises, this is how it is sunny. To your eye you can not detect a change in color within the samples from month to month, nevertheless the spectrophotometer is sensitive enough to measure subtlest of shifts in color.
- Thus giving us the understanding that the colour of a painting changes not merely if it is kept in the dark and brought in to the light, it is changing throughout its life however imperceptibly, in response into the level of light it receives.
- Since each color has the three attributes of hue value and intensity, it will require at the least two graphs of each and every color sample to tell a whole story associated with measurement of color as well as its changes. One graph, based on L*, shows Lightness or value, and another, in line with the a* & b* values show how that color moved through color space if it space was flat, like a normal artists color wheel.
Change of Color from Storage at nighttime
- It is clear that the changes we are measuring only become perceptible in extremes of painting and storage, such as for instance in a painting with large, thick areas of white that receive little light.
- The graphs below address this question, first is a graph for the lightness of Titanium White drawn down without medium during the early December. The Light Aged drawdown spent the entire year within the normal light and dark cycles which occur every single day. The Dark Aged drawdown dried in the light and was kept in total darkness until April. Then was immediately measured and gone back to total darkness until October, measured, after which brought out into the light and measured again after a week in normal day light.
- The Light aged sample measured lighter all the two times it had been measured throughout the year. The Dark aged sample showed an approximate .3 % lowering of lightness throughout the time it absolutely was at night. Soon after being brought back in to the light it regained it original color and matched the light aged sample in lightness.
- Nevertheless the “degree of color” component expressed into the a*b* graph illustrates how oil changes color as a result to light levels. The Light Aged sample moved in direction of zero, (zero is wholly neutral in color), the bleaching effect of the light made the oil paler in color throughout the year. The Gamblin Warm White measurement is merely for comparison to demonstrate how small would be the changes in the white our company is speaking about.
- The Dark Aged sample gained color from being kept in the dark, nevertheless when brought in to the light recovered its color to the level with regards to was placed into the dark. In other words it recovered its original color. Any difference would be most likely be imperceptible into the eye.
Improvement in Color When Medium is added
- Given that this is clear, let’s ask the question what the results are when one adds medium, which essentially adds more binder to your paint? The graph above shows what happened to Titanium White when 20% Galkyd was added. We possess the exact same form of movement we saw in pure paint. The Light Aged sample got less color throughout the year; the Dark aged sample gained in color at night, but nearly matched the light aged sample in color because of the end regarding the study.
The end result of Heat from the Color of Oil
- We also wanted to go through the effect of heat aging since we know that lots of oil paintings are stored in the dark in hot garages and attics throughout the summer months. And think about glazes? How can they perform being that they are so rich in binder. We were able to get a review of both questions by aging pure films of Galkyd within the light, dark, and hot dark.
- This graph is just a little difficult to see because a lot of points are clustered in one area. The Galkyd aged into the light just moved around one tight section of the graph, it’s color changing imperceptibly. And because Galkyd is pure binder it took on lots of color at nighttime, and even more so within the hot dark. But after a month of being gone back to the light, both samples recovered their color to just like the sample that had aged into the light the complete time.
- This test was the most dramatic illustration of paint/mediums aging at night for a year or higher, and then recovering their original color when cut back to the light.
- This is a good exemplory case of why we recommend using a varnish such as Gamvar when it comes to final coat on a painting instead of a coat of a painting medium. Gamvar, since it is not made from oil, will likely not proceed through these light/dark color shifts.
- The few graphs above are representative of the relatively large study we did, and our studies concur with the knowledge handed down to us through the centuries of oil painting, along with Henry Levinson’s tests.
- Oil colors in a dried oil painting take on color at nighttime, and bleach back out in the light. And then we unearthed that mediums act exactly the same way as pure oil colors.
- This leads to an additional recommendation: that work be brought away from storage before an expected viewing and place into bright light for some days.
- As artists we understand that our paintings have been in partnership with light, and therefore our work appears differently in different temperatures and degrees of light. Nevertheless the studies above also point out that light levels are constantly affecting the color in a painting. And we believe it is to be profound that the painting we thought was finished is subtly changing in reaction to where it really is hanging, enough time of day, together with brightness regarding the season.
- We now have always thought that a painting has two lives, usually the one it has on the easel while being created, therefore the second one that begins when the artist says, “it’s done.” This study implies that paintings in their second lives are not inanimate objects, they’ve been dynamic (always active or changing), in subtle ways.