Gainsborough Products, LLC

Oil Painting Restoration and Conservation Supplies Since 1974
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Photos of Ultraviolet Light Inspection using UVL-56, UVL-4P and UVL-5P UV Lights

Ultraviolet light reveals alterations such as inpainting, repairs and floating signatures on artwork that are normally invisible. Alterations to an original oil painting will stand out under UV light and will look darker than surrounding areas.

Shown below are examples of Gainsborough’s UVL-56, UVL-4P and UVL-5P ultraviolet lights in use. Results when using a UV lamp are most visible in a room with minimal light. These photos were taken in a room with the window coverings closed, but not complete darkness.

Click on the images to enlarge.

Scandanavian Landscape

14"x18"” Scandinavian oil painting in natural light.

Scandanavian Landscape with UVL-56, closer

The UVL-56 plug-in UV Lamp lights up a broad area to show more of the painting at one time, making it easier to compare inpainted areas with untouched areas of the painting. The 365 nm wavelength UV light provided by the UVL-56 is ideal for viewing oil paintings.

Circles indicate some of the inpainted areas.

Scandanavian Landscape with UVL-4P

The UVL-4P provides strong UV light in a battery powered flashlight. It lights a smaller area than the UVL-56, and its 365-400 nm wavelength range produces some purple cast, but it still shows the inpainted areas clearly.

Circles indicate some of the inpainted areas.

Scandanavian Landscape with UVL-5P

The UVL-5P battery powered flashlight emits a mix of 365 nm and 390 nm wavelengths. The UVL-5P beam is smaller than that of the UVL-4P, but it is less purple and closer to the invisible 365 nm wavelength. The UVL-5P can switch between UV and white light during inspection, making it easier to compare the painting under UV and normal lighting.

The circle indicates some of the inpainted areas.

Scandanavian Landscape with UVL-5P flashlight

The UVL-5P white LED light facilitates comparison of normal and UV-illuminated paintings, especially in dimly lit rooms.

Seascape in natural light.

Seascape oil painting with original signature, except for the first letter "G". The "G" was probably removed by accident during cleaning and then painted back in. This photo shows the signature in natural light and the following photos show how the "G" appears dark under UV light, while the rest of the signature is nearly invisible under UV light.

Seascape signature in natural light.

Close-up of the artist’s signature on the seascape oil painting. In natural light, the initial "G" does not stand out from the rest of the signature.

Seascape with UVL-56.

The broad illumination of the UVL-56 UV lamp shows the artist’s signature and the lower left quarter of the painting.

Seascape signature with UVL-56.

Close-up of the signature using the UVL-56 UV lamp showing the dark "G", indicating that it was added later than the original signature.

Seascape with UVL-4P.

UVL-4P’s smaller, but intense beam showing the artist’s signature.

Seascape signature with UVL-4P.

Close-up of the signature using the UVL-4P UV lamp showing the dark "G".

Seascape with UVL-5P.

UVL-5P shows the artist's signature with less purple hue.

Seascape signature with UVL-5P.

Close-up of the signature using the UVL-5P UV lamp showing the dark "G".