An overall, even network of cracks on an old oil painting is called “crackle” or “craquelure” and is normal. But when those cracks take on other patterns, such as this bullseye pattern visible in the sky, there has been a damage event. The painting suffered an impact at the center of that circular cracked region, and since the many layers of the painting could not flex the same amount, it resulted in uneven cracking.
Photo credit: Alaska State Museum collection 2007-12-1
Sometimes there are cracks with large open gaps in the top paint layer, sometimes called “alligatoring. It can be caused by a mismatch of the paints used for the different layers. If the edges of the paint on both sides of the crack are not lifting, the paint layer is probably still stable.
Photo credit: Sheldon Jackson Museum collection SJ-V-D-8
In this case, the top layer of paint has not been able to shrink as much as the layer below, and there are raised ridges that look like cracks. Paint has worn off the tops of these ridges and caused loss that looks like cracks. This is another paint mismatch issue.
Photo credit: Alaska State Museum collection II-B-1412
This painting is quite dirty. The varnish is discolored and there is mottled yellowing and grime.
Photo credit: Alaska State Museum collection 2013-24-1
Here is a close-up of the mottled yellowing and discoloration of the varnish in a detail of the same painting. It is especially visible in the white areas.
Photo credit: Alaska State Museum collection 2013-24-1
Here is an image of a painting in the process of being cleaned by a conservator. The side with the pack horses is yellowed and dirty. The side with the person has had the varnish removed. If a painting looks yellowed, it might be because the varnish is aged or dirty.
Photo credit: Alaska State Museum collection 2000-27-1
This is another image of a painting during professional cleaning. The area with the cabin has been cleaned of its aged, yellow varnish. Painting with a warm yellowish tone might be the intent of the artist, but more likely it is dirty or has aged varnish and needs to be cleaned.
Photo credit: Alaska State Museum collection V-A-604
This painting has been scraped and there are flakes of lifting paint along the damage. This is a serious condition issue and the paint flakes are at risk of detaching.
Photo credit: Alaska State Museum collection 91-2-1
Here is an example of a scraped area where the paint flakes have detached, leaving an area of loss and disfigurement. The paint is also lifting along the edges of the loss, risking further damage.
Photo credit: Alaska State Museum collection V-A-147
This image shows how paint chips along cracks can have their edges lift up precariously. This is called “tenting” and the paint flakes are at great risk of loss. In this case, there has already been considerable loss.
Photo credit: Alaska State Museum collection III-R-299
This religious icon has a border area of gilding. The exposed reddish area under the gold is a layer of clay called “bole” that gold leaf sticks to during the process of gilding. Some sacred objects receive devotional touching as part of their use, and this wear is an important part of the history of this icon.
Photo credit: Alaska State Museum collection III-R-299
Here is a detail of a much larger artwork. Artists often experiment with their media, and in this case the orange drips are an intentional part of this painting. The ends of the drips have remained tacky many years later.
Photo credit: Alaska State Museum collection 2001-6-1
Very thick paint application may include raised areas of paint and visible strokes. This kind of heavy paint application is called “impasto” and the tips of the ridges and peaks can be vulnerable to damage. The texture of the paint surface can also trap dirt and dust.
Photo credit: Alaska State Museum collection 90-15-1
The vertical line in the canvas parallel to the frame is a stretcher mark, from the canvas resting on the structure of the wood behind it. This is similar to impact damage. Many issues regarding cracks and marks in the paint layer can be better seen with raking light (a strong light source that shines on the surface at an angle). Play with your lighting or even use a flashlight to inspect the paint surface.
Photo credit: Alaska State Museum collection V-A-174
The white area is a kind of backing board. This protects the back of the painting, prevents the canvas from flexing like a sail when it is moved around, and keeps the back of the painting clean. Without a dust cover, dust and debris can get in between the canvas and the stretcher/strainer and form a dirt pocket that can damage the painting.
Photo credit: Alaska State Museum collection
This is an old dust cover that has torn. Often, when a dust cover like this is removed there is a piece of acidic cardboard in the frame behind it as a backing board. This dust cover has important writing and a gallery label on it. These need to be documented and retained.
Photo credit: Alaska State Museum collection 2005-24-1
This image shows the back of a painting with no backing board or dust cover. This is an example of a “stretcher” or the structural support at the four edges of a painting that the canvas wraps around. In the corners, you see little wedges of wood called “stretcher keys”. If you don’t have some mechanism at the corner where the tension can be adjusted, you don’t have a stretcher…you have a “strainer” which looks similar but the corners are simple and have no way to adjust them. If you can see the corners, check to see if any of those stretcher keys might be missing.
Photo credit: Alaska State Museum
When condition reporting, always indicate what is going on with the back of the painting and with the hanging hardware. If there are rusted screw eyes and old corroded/darkened braided wire, the painting is not safe to hang without replacing the hanging hardware.
Photo credit: Alaska State Museum collection V-C-20
Old wire can snap without warning, and screw eyes have very short threaded shanks that can loosen and pull out of their holes. It is wise to be suspicious of hanging hardware. Since decisions to loan or exhibit an artwork need to know this information, it is good to capture in the condition report.
Photo credit: Alaska State Museum collection V-C-20
Many collections have historic signage on wood or metal substrates. These often have damaged, flaking paint.
