This summary was produced to assist Museum Victoria’s Conservation team to interpret results of ultra-violet (UV) light examination. The table below lists materials with published results of UV light examination from conservation journals and other sources, including personal observations. By no means an exhaustive list, it is reproduced here in the hope that it will be of benefit to other conservators using this examination technique. These results would benefit from further testing and research.
UV light is a form of electromagnetic radiation, along with visible light, infrared, x-rays etc. (see Figure 1, below). UV light radiates at shorter wavelengths than visible light and cannot be seen by the human eye. However, when UV light is absorbed by certain materials, it is reflected back towards the eye as longer wavelength visible radiation, or visible light. This phenomenon is referred to as UV-induced visible fluorescence.
Observation of this fluorescence can be used by conservators as a non-destructive analytical technique to aid in the examination of objects. The presence of fluorescence may assist with materials identification, detecting insect damage or surface coatings, and uncovering areas of previous restoration. The colours of the observed fluorescence will depend on the material and on the wavelength of UV light used. For example, many adhesives fluoresce under long-wave UV but do not fluoresce at all under short-wave UV. On the other hand, many mineral specimens fluoresce under short-wave UV.
Limitations
Fluorescence is a useful tool for identification, however caution should be taken when drawing conclusions based solely on examination with UV light. It may be easily misinterpreted, or produce misleading results due to age or surface dirt obscuring fluorescing materials underneath. Further testing may be required. UV light can cause damage to collection objects, and while the amount of radiation absorbed by an object during examination will be small, it is recommended that exposure time should be limited.
Safety
Long term exposure to UV radiation can lead to serious and irreversible vision problems, including cataracts, glaucoma and macular degeneration. UV radiation may also increase the risk of skin cancer, and exposure to unprotected skin should be minimised (World Health Organisation 2016). When carrying out examination using UV light, the following minimum personal protective equipment is required:
- UV filtering safety glasses
- Long sleeves (e.g. lab coat)
- Nitrile gloves
Interpreting results
The colours of the observed fluorescence will depend on the material and the wavelength of the UV light that is being used. It is important to use a UV lamp with the appropriate wavelength for the questions at hand. Remember also that as with any examination technique, avoid drawing conclusions from the results of UV-induced visible fluorescence examination alone.
Range Wavelength Abbreviations
Short-wave 100-280nm SW UVC
Mid-wave 280-315nm MW UVB
Long-wave 315-400nm LW UVA
|
OBJECTS
|
UV Lamp |
Results |
Notes |
Reference/Source |
|
Ceramics |
|
|
UV examination is most useful to determine the presence of previous repairs as many adhesives and fills fluoresce. (See Adhesives, Consolidants, Binders, Varnishes & Coatings section). |
|
|
Hard-paste porcelain |
Short-wave UV
|
Fluoresces dim pink |
|
Simpson-Grant 2000 (B) |
|
Soft-paste porcelain |
Short-wave UV
|
Fluoresces milky white |
|
Simpson-Grant 2000 (B) |
|
Glass |
|
|
The colour of fluorescence is not so much characteristic of the type of glass, but rather is indicative of the refining agents, the furnace atmosphere and melting temperature. |
Newton & Davison 1989 |
|
Borosilicate glass |
|
Does not fluoresce |
|
Simmons 1995, p. 169. |
|
Crystal/lead glass |
Short-wave UV
|
Fluoresces dramatic icy blue |
The colour can change to green if larger amounts of lead are present. |
Simpson-Grant 2000 (B); Newton & Davison 1989 |
|
Soda- Lime glass |
Long-wave UV |
Fluoresces yellow-green |
|
Simmons 1995, p. 169. |
|
Uranium glass |
Long-wave UV |
Fluoresces bright yellow/green |
|
Simpson-Grant 2000 (B) |
|
Stone |
|
|
|
|
|
Aged marble, limestone and alabaster |
Long-wave UV |
Patina may exhibit mottled fluorescence |
|
Simpson-Grant 2000 (B) |
|
Freshly cut marble, limestone and alabaster |
Not specified |
Does not fluoresce significantly
|
|
Simpson-Grant 2000 (B) |
|
Ivory and Bone |
|
|
|
|
|
New ivory and bone |
Long-wave UV |
Fluoresces bright white |
|
Simpson-Grant 2000 (B) |
|
Old ivory and bone |
Long-wave UV |
Fluoresces a subdued, mottled yellow |
|
Simpson-Grant 2000 (B) |
|
Metals |
|
|
Generally metals do not fluoresce, however some coatings applied to the surface may fluoresce. See Adhesives, Consolidants, Binders, Varnishes & Coatings section |
|
|
Plastics |
|
|
Optical brighteners (OBs) introduced into plastics in 1950s |
Mustalish 2000, p.135 |
|
Wood |
|
|
Some coatings applied to the surface may fluoresce. See Adhesives, Consolidants, Binders, Varnishes & Coatings section |
|
|
Old wood |
Long-wave UV |
Patina may fluoresce in mottled tones |
|
Simpson-Grant 2000 (B) |
|
Sumac |
Long-wave UV |
Strong fluorescence (Colour not specified) |
|
Simpson-Grant 2000 (B) |
|
Textiles |
|
|
|
|
|
Textiles treated with optical brighteners (OB’s) |
Long-wave UV |
Fluoresce brightly |
OBs used in silks and wool from 1840s; in polyester, polyacrylonitrile, viscose rayons, cellulose acetate and nylon from 1960s. Used in laundry detergents from 1830s, textiles washed in detergents with OB’s may also fluoresce. |
Simpson-Grant 2000 (B); Mustalish 2000, pp.134-135. |
|
Wool |
Long-wave UV |
Fluoresces blue-white
|
Fluorescence occurs when keratin begins to decompose or due to treatments, which disrupt disulphide bonds, e.g. oxidizing agents. |
Collins et al. 1988, pp. 349–51 |
|
ADHESIVES, CONSOLIDANTS, BINDERS, VARNISHES & COATINGS |
UV Lamp |
Results |
Notes |
Reference/Source |
|
Beeswax |
Short-wave UV |
Fluoresces bright pale orange |
|
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
Long-wave UV |
Fluoresces bright pink/orange |
|
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
|
Carnauba |
Long-wave UV |
Fluoresces yellow-brown |
Thin wax coatings on furniture are generally not visible with hand held UV lamps.
|
Rivers & Umney 2013, p. 610 |
|
Cellulose |
Long-wave UV |
Fluoresces bright white |
|
Rivers & Umney 2013, p. 610 |
|
Cellulose acetate (UHU) |
Long-wave UV |
Milky white fluorescence |
|
Simpson-Grant 2000 (B) |
|
Cellulose Nitrate |
Long-wave UV |
Fluoresces greenish yellow |
|
Simpson-Grant 2000 (B) |
|
Copal |
Short-wave UV |
Fluoresces matte, deep orange – dark yellow |
|
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
Long-wave UV |
Fluoresces bright, light orange |
|
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
|
Dammar |
Short-wave UV |
Fluoresces dull yellow green |
|
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
Long-wave UV
|
Fluoresces variable colours, green/yellow to green/ white |
|
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
|
Fluoresces greenish white |
|
Rivers & Umney 2013, p. 610 |
||
|
Dammar and Wax |
Short-wave UV |
Fluoresces very dull orange |
|
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
Long-wave UV |
Fluoresces slight, dull orange |
|
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
|
Dextrin |
Long-wave UV |
Fluoresces blue-white |
|
Jirat-Wasiutynski 1986, p.24 |
|
Egg white |
Short-wave UV |
Fluoresces pale yellow |
|
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
Long-wave UV |
Fluoresces variable colours dull pink/orange to bright light yellow |
|
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
|
Epoxy adhesives |
Long-wave UV |
Fluoresces bright yellowish white |
|
Simpson-Grant 2000 (B) |
|
Gum Arabic |
Short-wave UV |
Absorbs UV |
|
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
Long-wave UV |
Absorbs UV |
|
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
|
Hide glue |
Long-wave UV |
Fluoresces bright white |
|
Rivers & Umney 2013, p. 610 |
|
Laropal K80 (Ketone resin N) |
Short-wave UV |
Fluoresces purple |
|
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
Long-wave UV |
Fluoresces purple |
|
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
|
Linseed oil |
Short-wave UV |
Fluoresces deep yellow |
|
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
Long-wave UV |
Fluoresces orange |
|
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
|
Mastic
|
Short-wave UV |
Fluoresces dull yellow/green |
|
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
Long-wave UV
|
Fluoresces variable colours, green/yellow to green/ white |
|
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
|
Fluoresces greenish white |
|
Rivers & Umney 2013, p. 610 |
||
|
Mowilith 50 (Poly Vinyl Acetate) |
Short-wave UV |
Fluoresces dull light orange |
|
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
Long-wave UV |
Fluoresces slight dull yellow |
|
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
|
Natural resins |
Long-wave UV |
Fluoresces green, yellowish or milky grey |
|
Simpson-Grant 2000 (B) |
|
Old varnish |
Not specified |
Fluorescence appears milky but transparent |
Under UV light a painting with a smooth coat of old varnish looks milky but fairly transparent. Interference such as attempts to remove the varnish, local retouching & repairs can be clearly seen as darker patches. |
Hours 1976, p.45 |
|
Oriental Lacquer |
Long-wave UV |
Varies from no fluorescence to muted orange to bright orange. |
|
Rivers & Umney 2013, p. 610 |
|
Paraffin wax |
Long-wave UV |
Fluoresces blue |
Thin wax coatings on furniture are generally not visible with hand held UV lamps. |
Rivers and Umney 2013, p. 610 |
|
Paraloid B72 |
Not specified |
No fluorescence |
|
Simpson-Grant 2000 (B); Pemberton & Kowalski pers. comm. 6 September 2016 |
|
Poly vinyl acetate |
Long-wave UV |
Blueish milky fluorescence |
|
Simpson-Grant 2000 (B) |
|
Regalrez (hydrocarbon resin) |
Short-wave UV |
Fluoresces dull yellow |
|
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
Long-wave UV |
Fluoresces pale orange/yellow |
Similar to Dammar |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
|
Shellac |
Short-wave UV |
Fluoresces dull orange |
|
Pemberton & Kowalski pers. comm. 6 September 2016. |
|
Long-wave UV |
Fluoresces bright orange |
Shellac that has had extensive sun exposure may exhibit yellow-green fluorescence |
Simpson-Grant 2000 (B); Rivers & Umney 2013, p. 610; Pemberton & Kowalski pers. comm. 6 September 2016 |
|
|
Some waxes |
Long-wave UV |
Fluoresces bright white |
|
Simpson-Grant 2000 (B) |
|
Stand oil |
Short-wave UV |
Fluoresces orange – slightly grey |
|
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
Long-wave UV |
Fluoresces orange |
|
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
|
Synthetic resins |
Long-wave UV |
Vary from no fluorescence to blue-white or lavender. Some aged synthetic resins may exhibit a greenish-white fluorescence. |
Synthetic resins can become more fluorescent over time, making it difficult to distinguish them from natural resins. |
Rivers & Umney 2013, p. 388. 610; Pemberton & Kowalski pers. comm. 6 September 2016 |
|
Tempera |
Short-wave UV |
Fluoresces pale yellow |
Type of tempera not classified in available prepared sample |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
Long-wave UV |
Fluoresces bright pale orange |
Type of tempera not classified in available prepared sample |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
PIGMENTS, INKS & DYES
|
UV Lamp |
Results |
Notes |
Reference/Source |
|
Red |
|
|
|
|
|
Alizarin |
Short-wave UV |
Dull orange colour change |
Oil binder |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
Long-wave UV |
Dull orange colour change |
Oil binder |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
|
Not specified |
Fluoresces pale violet |
|
Museum of Fine of Boston n.d. |
|
|
Alizarin Lake (Synthetic) |
Not specified |
No fluorescence |
|
Fitzhugh 1997, p.124 |
|
Cadmium red |
Not specified
|
Fluoresces red |
|
Stuart 2007, p.77 |
|
No fluorescence |
Oil binder |
Pemberton & Kowalski pers. comm. 6 September 2016 |
||
|
Carmine |
Not specified |
Fluoresces vivid pink |
True for carmine from both cochineal and kermes beetles. |
Feller 1986, p.255, 273. |
|
Cinnabar, pure |
Not specified |
Fluoresces dark red |
|
Eastman Kodak Company 1987 |
|
Cinnabar substitute (lithol red) |
Not specified |
Fluoresces cinnabar red |
|
Eastman Kodak Company 1987 |
|
Cinnabar substitute (Permanent red) |
Not specified |
Fluoresces carmine |
|
Eastman Kodak Company 1987 |
|
Crimson lake |
Short-wave UV |
Fluoresces pale orange Dull orange colour change |
Oil binder |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
Long-wave UV |
Fluoresces pale orange Dull orange colour change |
Oil binder |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
|
Dragon’s blood |
Short-wave UV |
Fluoresces slight, pale orange |
|
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
Long-wave UV |
Fluoresces slight, pale orange |
|
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
|
Eosin |
Not specified
|
Not specified |
Fades rapidly in sunlight |
Museum of Fine of Boston n.d. |
|
Fluoresces bright orange |
|
Chapman 2000. |
||
|
Indian red |
Short-wave UV |
Dull orange colour change |
Oil binder |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
Long-wave UV |
Orange colour change |
Oil binder |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
|
Lac Lake |
Not specified |
No fluorescence |
|
Fitzhugh 1997, p.124 |
|
Madder |
Not specified |
Fluoresces fiery yellow red |
|
Gettens & Stout 1966, p.126 |
|
Fluoresces dull orange |
Madder Carmine will also fluoresce orange (Feller p.274) |
Fitzhugh 1997, p.124 |
||
|
Short-wave UV |
Fluoresces bright yellow-orange |
Oil binder |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
|
Long-wave UV |
Fluoresces bright yellow-orange |
Oil binder |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
|
Fluoresces bright yellow-orange |
|
Museum of Fine of Boston n.d. |
||
|
Red ochre |
Not specified |
No fluorescence |
|
Stuart 2007, p.77 |
|
Red lead |
Not specified |
Fluoresces dark red |
|
Stuart 2007, p.77 |
|
Long-wave UV |
Absorbs |
|
Fiske & Stiber Morenus 2004, p.26 |
|
|
Red lead pure |
Not specified |
Fluoresces dark red |
|
Eastman Kodak Company 1987 |
|
Red lead substitute (helio red) |
Not specified |
Fluoresces reddish-brown |
|
Eastman Kodak Company 1987 |
|
Red lead substitute (lac red) |
Not specified |
Fluoresces orange-red |
|
Eastman Kodak Company 1987 |
|
Safflower red |
Long-wave UV |
Fluoresces orange |
|
Fiske & Stiber Morenus 2004, p.31 |
|
Vermillion |
Short-wave UV |
Orange colour change |
Oil binder |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
Long-wave UV |
Absorbs, appears dark red brown |
|
Fiske & Stiber Morenus 2004, p.26, 31 |
|
|
Orange colour change |
Oil binder |
Pemberton & Kowalski pers. comm. 6 September 2016 |
||
|
Not specified |
Fluoresces red |
|
Stuart 2007, p.77 |
|
|
Orange |
|
|
|
|
|
Cadmium orange |
Short-wave UV |
No fluorescence |
Oil binder |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
Long-wave UV |
No fluorescence |
Oil binder |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
|
Yellow |
|
|
|
|
|
Cadmium yellow
|
Not specified
|
Fluoresces light red |
|
Stuart 2007, p.77 |
|
No fluorescence |
Oil binder |
Pemberton & Kowalski pers. comm. 6 September 2016 |
||
|
Cadmium yellow – Light |
Short-wave UV |
Orange colour change |
Liquitex Acrylic |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
Long-wave UV |
Orange colour change |
Liquitex Acrylic |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
|
Cadmium yellow – Pale |
Short-wave UV |
Fluoresces dull orange/yellow
|
Oil binder
|
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
Dark green colour change |
Liquitex Acrylic |
Pemberton & Kowalski pers. comm. 6 September 2016 |
||
|
Long-wave UV |
Fluoresces dull orange/yellow
|
Oil binder
|
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
|
Dark green colour change |
Liquitex Acrylic |
Pemberton & Kowalski pers. comm. 6 September 2016 |
||
|
Chrome yellow |
Not specified |
Fluoresces red |
|
Stuart 2007, p.77 |
|
Gamboge |
Not specified |
Fluoresces olive green |
|
Wilson 2014 |
|
Hansa yellow light |
Short-wave UV |
Lime green colour change |
Liquitex Acrylic |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
Long-wave UV |
Lime green colour change |
Liquitex Acrylic |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
|
Indian Yellow |
Short-wave UV |
Fluoresces dull orange |
Liquitex Acrylic |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
Long-wave UV |
Fluoresces bright yellow, sometimes orange-yellow |
|
Feller 1986, pp.32-33; Pemberton & Kowalski pers. comm. 6 September 2016 |
|
|
Naples yellow |
Short-wave UV |
Dull, slight orange colour change |
Oil binder |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
Long-wave UV |
Dull, slight orange colour change |
Oil binder |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
|
Not specified |
Fluoresces light red |
|
Stuart 2007, p.77 |
|
|
Nickel titanate yellow |
Short-wave UV |
Dull yellow colour change |
Oil binder |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
Long-wave UV |
Dull yellow colour change |
Oil binder |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
|
Orpiment |
Not specified |
Fluoresces light yellow |
|
Stuart 2007, p.77 |
|
Zinc yellow |
Not specified |
Fluoresces bright red |
|
Stuart 2007, p.77 |
|
Short-wave UV |
Green colour change |
Oil binder |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
|
Long-wave UV |
Green colour change |
Oil binder |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
|
Green |
|
|
|
|
|
Chromium oxide |
Long-wave UV |
Absorbs UV light, appearing dark |
Windsor & Newton Watercolour |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
Cobalt Green |
Short-wave UV |
Bright green/yellow colour change |
Oil binder |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
Long-wave UV |
Bright green/yellow colour change |
Oil binder |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
|
Emerald Green (copper aceto-arsenite) |
Not specified |
Absorbs UV light, appearing very dark |
This is true whether the colour is bright green or discoloured tan, or whether layer is thin or thick. |
Zieske 2002, p.93 |
|
Green earth (Terre Verte) |
Not specified |
Fluoresces bright blue |
|
Stuart 2007, p.77 |
|
Short-wave UV |
Lighter green colour change |
Oil binder |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
|
Long-wave UV |
Yellow colour change |
Oil binder |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
|
Phthalocyanine green |
Not specified |
No fluorescence |
|
Stuart 2007, p.77 |
|
Prussian green |
Short-wave UV |
Lighter green colour change |
Oil binder |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
Long-wave UV |
No fluorescence |
Oil binder |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
|
Verdigris |
Not specified |
No fluorescence |
|
Stuart 2007, p.77 |
|
Viridian |
Not specified |
Fluoresces bright red |
|
Stuart 2007, p.77 |
|
Blue |
|
|
|
|
|
Antwerp blue |
Short-wave UV |
Green colour change |
Oil binder |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
Long-wave UV |
Dull, green colour change |
Oil binder |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
|
Azurite |
Not specified |
Fluoresces dark blue |
|
Stuart 2007, p.77 |
|
Cerulean blue |
Not specified |
Fluoresces lavender blue |
|
Stuart 2007, p.77 |
|
Short-wave UV |
Dull aqua colour change |
Oil binder |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
|
Long-wave UV |
Bright aqua colour change |
Oil binder |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
|
Cobalt blue |
Not specified |
Fluoresces red |
|
Stuart 2007, p.77 |
|
Short-wave UV |
Slight green colour change |
|
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
|
Dayflower |
Long-wave UV |
Fluoresces warm, light to medium grey or blue-grey |
Can be difficult to differentiate from Indigo. |
Fiske & Stiber Morenus 2004, p.31 |
|
Egyptian blue |
Not specified |
Fluoresces purple |
|
Stuart 2007, p.77 |
|
Indigo |
Not specified |
Fluoresces dark purple |
|
Stuart 2007, p.77 |
|
Long-wave UV |
Fluoresces light to medium blue-grey |
Can be difficult to differentiate from Dayflower. |
Fiske & Stiber Morenus 2004, p.31 |
|
|
Phthalocyanine blue |
Not specified |
No fluorescence |
|
Stuart 2007, p.77 |
|
Prussian blue |
Not specified |
No fluorescence |
|
Stuart 2007, p.77 |
|
Long-wave UV |
Fluoresces dark to medium blue |
Brighter blue than dayflower and indigo. |
Fiske & Stiber Morenus 2004, p.31 |
|
|
Smalt |
Not specified |
Fluoresces light purple |
|
Stuart 2007, p.77 |
|
Ultramarine blue, pure |
Not specified |
Dark blue-violet |
|
Eastman Kodak Company 1987 |
|
Ultramarine blue, deep |
Short-wave UV |
Slight green colour change |
Oil binder |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
Victoria Blue |
Not specified |
Fluoresces dark blue-violet |
Substitute for pure ultramarine. |
Eastman Kodak Company 1987 |
|
Purple |
|
|
|
|
|
Cobalt violet |
Short-wave UV |
Fluoresces dull pale purple |
Oil binder |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
Long-wave UV |
Fluoresces pale purple |
Oil binder
|
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
|
Brown |
|
|
|
|
|
Bistre ink |
Not specified
|
Ink lines can fluoresce |
Fluorescence more likely in un-aged inks. |
Baker 1983, p.161 |
|
Iron gall ink |
Not specified |
Absorbs UV light with no fluorescence |
|
Stuart 2007, p.77 |
|
Long-wave UV |
Appears black |
|
Jirat-Wasiutynski 1986, p.23; Pemberton & Kowalski pers. comm. 6 September 2016 |
|
|
Not specified |
Fluorescent halo around aged ink lines recto and verso |
No fluorescence seen in un-aged sample or light-aged sample. Ink lines themselves don’t fluoresce. |
Baker 1983, p.161 |
|
|
Black |
|
|
|
|
|
Carbon |
Not specified |
Absorbs, appears black |
A Chinese ink stick (also carbon-based) was found to fluoresce under ultraviolet in an oven-aged sample. |
Baker 1983, p.161; |
|
Lamp Black |
Short-wave UV |
Bright green colour change |
Oil binder |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
Long-wave UV |
Green colour change |
Oil binder |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
|
White |
|
|
|
|
|
Calcium Carbonate/Chalk |
Long-wave UV |
Fluoresces medium purple |
|
Jirat-Wasiutynski 1986, p.23 |
|
Not specified |
Fluoresces dark yellow |
|
Stuart 2007, p.77 |
|
|
Chalk, ground |
Not specified |
Fluoresces red to brown |
|
Eastman Kodak Company 1987 |
|
Chalk, precipitated |
Not specified |
Fluoresces black |
|
Eastman Kodak Company 1987 |
|
Chalk, natural |
Not specified |
Fluoresces dark yellow |
|
Eastman Kodak Company 1987 |
|
Chalk, siliceous |
Not specified |
Fluoresces red-violet |
|
Eastman Kodak Company 1987 |
|
Gypsum |
Not specified |
Fluoresces violet |
|
Stuart 2007, p.77 |
|
Lead white |
Short-wave UV |
Dull, pale orange colour change |
Binder type not identified in sample tested |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
Long-wave UV
|
Fluoresces reddish-purple |
|
Jirat-Wasiutynski 1986, p.23 |
|
|
Fluoresces bright pale orange |
Binder type not identified in sample tested |
Pemberton & Kowalski pers. comm. 6 September 2016 |
||
|
Not specified |
Fluoresces brown-pink |
|
Stuart 2007, p.77 |
|
|
Leaded zinc white |
Long-wave UV |
Fluoresces deep yellow orange with slight greenish tint |
|
Jirat-Wasiutynski 1986, p.23 |
|
Lithopone |
Not specified |
Fluoresces orange-yellow |
|
Stuart 2007, p.77 |
|
Titanium dioxide |
Short-wave UV |
Purple/grey colour change |
Windsor & Newton Watercolour
|
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
Short-wave UV |
Intense purple colour change |
Liquitex Acrylic |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
|
Long-wave UV |
Fluoresces deep purple |
|
Jirat-Wasiutynski 1986, p.23 |
|
|
Long-wave UV |
Purple colour change |
Windsor & Newton Watercolour and Liquitex Acrylic |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
|
Not specified |
Mixtures with zinc oxide fluoresce green-yellow |
|
Museum of Fine of Boston n.d. |
|
|
Titanium (unbleached) |
Short-wave UV |
Deep purple colour change |
Liquitex Acrylic |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
Long-wave UV |
Deep purple colour change |
Liquitex Acrylic |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
|
Zinc white |
Short-wave UV |
Fluoresces dull creamy yellow |
Oil binder |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
Long-wave UV |
Fluoresces bright creamy yellow |
Oil binder |
Pemberton & Kowalski pers. comm. 6 September 2016 |
|
|
Fluoresces yellow green |
|
Jirat-Wasiutynski 1986, p.23 |
||
|
Not specified |
Fluoresces yellow |
|
Museum of Fine of Boston n.d. |
|
PAPER, PARCHMENT & PHOTOS
|
UV Lamp |
Results |
Notes |
Reference/Source |
|
Bio deterioration of paper
|
Not specified |
Fluoresces Grey |
Used to observe damage to paper caused by bacteria or fungi that may not visible to the naked eye. |
Stuart 2007, p.77 |
|
Foxing |
Not specified |
Fluoresces (colour not specified) |
UV fluorescence is detected in the early stage of foxing. |
Choi 2007, p.142 |
|
Optical Brighteners (OB) in photographs |
Long-wave UV |
Fluoresces bluish white. |
OB’s may be washed out in water. Used in raw paper stock, emulsions, baryta, processing chemicals & surface coatings from the 1950’s. A bright appearance can also be attributed to other factors incl. gelatin (which has a natural fluorescence) and baryta coatings. |
Messier et al. 2005, p.2 |
|
Optical Brighteners in Paper |
|
Fluoresces bright white |
Common use in paper from 1945. |
Mustalish 2000, p.133; Leclerc & Flieder 1992, p.257. |
|
Paper |
Long-wave UV |
Fluoresces (colour not specified) |
Fluorescence of old paper changes dramatically upon washing |
Jirat-Wasiutynski 1986, p.24; Cohn 1982 |
|
Parchment |
Not specified |
May fluoresce bright yellow or purple or no fluorescence depending on state of degradation
|
If parchment is water damaged or degraded it will not fluoresce. |
Melzer, Pers. Comm. 15th April 2016. |
|
Bleach |
|
|
|
|
|
Sodium borohydride |
Long-wave UV |
Fluoresces bright white |
|
Jirat-Wasiutynski 1986, p.24. |
|
NATURAL HISTORY
|
UV Lamp |
Results |
Notes |
Reference/Source |
|
Bird Pigments |
|
UV fluorescence is a stable attribute of some feather pigments, and a light-sensitive attribute in others.
|
Feathers whose pigments are not directly fluorescent may still undergo appearance changes under an UV light source as a consequence of light aging. Fluorescence is demonstrated to be an early marker of chemical change, and can be used to detect such change before it is day-light visible or can be measured. |
Pearlstein et al, 2014 |
|
Porphyrins (brown) |
Long-wave UV |
Fluoresces purple/magenta.
|
Light sensitive & often not detectable in museum specimens due to light damage. |
Hill 2010
|
|
Psittacofulvins (red & yellow) |
Long-wave UV |
Fluoresces yellow, orange or green. |
Unique to Psittaciformes. May be combined with blue structural colouration to produce secondary colours. |
Lagorio et al. 2015; Hill 2010
|
|
Spheniscin (yellow) |
Long-wave UV |
Fluoresces blue |
Unique to Sphenisciformes. |
Lagorio et al 2015 |
|
Invertebrate Colouration |
|
|
Ethanol in which UVF specimens are stored may gradually become fluorescent itself |
Welsh et al 2012 |
|
Beta-carboline |
Long-wave UV |
Fluoresce blue-green |
Scorpions & Spiders, including fossilised specimens |
Lagorio et al. 2015
|
|
Green Fluorescent Protein (GFP) |
Long-wave UV |
Fluoresces green |
Marine Invertebrates especially Aequorea Victoria (Crystal Jelly),Corals. |
Gaffin et al. 2014; The Smithsonian Walter Reed Biosystematics Unit n.d.; Lagorio et al. 2015
|
|
Guanine |
Long-wave UV |
Fluoresces Red, Orange or Green |
Fish |
Lagorio et al. 2015
|
|
Pterins |
Long-wave UV |
Fluoresces blue |
Moths and Butterflies, fly and beetle larvae, millipedes.
|
Lagorio et al. 2015; Welsh et al 2012. |
|
Schiff Bases |
Long-wave UV |
Fluoresces blue
|
Bees |
Lagorio et al. 2015
|
|
Mineral Specimens
|
All ranges |
Many colours |
UVF is too inconsistent to be a helpful identification tool. Gemstones which fluoresce: ruby, kunzite, diamond and opal. |
Wilkins 1999; King 2015; Henkel 1988. |
|
PESTS & PESTICIDES
|
UV Lamp |
Results |
Notes |
Reference/Source |
|
Mercuric Chloride (corrosive sublimate) -pesticide |
Long-wave UV |
Fluoresces cream, yellow, peach, orange or red. |
Mercuric chloride Hg (II) breaks down over time to mercurous chloride Hg (I). Hg (I) is often a fluorescent under UV light. |
Purewal & Colston 2014. |
|
Mould |
|
|
UV fluorescence gradually increases and decreases depending on life cycle of fungi.
|
Florian 1997 |
|
Urine |
|
Cat urine fluoresces orange with a bright yellow halo. |
|
Pemberton Pers. Comm. 15th April 2016 |
References
Baker, CA 1983, ‘A comparison of drawing inks using ultraviolet and infrared light examination techniques’, Application of science in examination of works of art: proceedings of the seminar, September 7-9, Boston, pp.159-163.
Chapman, J 2000, Glebe Stamps, viewed 15 April 2016, <http://www.glebecoins.net/kgv/The_KGV_1d_Red/the_kgv_1d_red.htm>.
Choi, S 2007, ‘Foxing on paper: A literature review’, in Journal of the American Institute of Conservation, vol. 46 (2), pp. 137-152.
Collins S, Davidson S, Greaves PH, Healy, M, and Lewis, DM 1988, ‘The natural fluorescence of wool’, Journal of the Society of Dye Chemists, vol. 104, pp. 348-352.
Eastman Kodak Company 1987, Ultraviolet and Fluorescence Photography, Publication No. M-27, Eastman Kodak Ltd, Rochester, New York.
Feller, R (ed.) 1986, Artist’s Pigments: A Handbook of Their History and Characteristics, Volume 1, National Gallery of Art, Washington.
Fiske, B and Stiber Morenus, L 2004, ‘Ultraviolet and Infrared Examination of Japanese Woodblock Prints: Identifying Reds and Blues’, The Book and Paper Group Annual, 23, pp.21-32.
Fitzhugh, E (ed.) 1997, Artists Pigments: A Handbook of Their History and Characteristics, vol. 3, National Gallery of Art, Washington.
Gaffin, DD, Bumm, LA, Taylor, MS, Popokina, NV and Mann, S 2012, ‘Scorpion fluorescence and reaction to light,’ Animal Behaviour, vol. 83, pp. 429-436.
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Henkel, G 1988, ‘The Henkel Glossary of Fluorescent Minerals’, Journal of the Fluorescent Mineral Society, vol. 15.
Hill, G 2010, Bird Colouration, National Geographic, Washington D.C.
Hours, M 1976, Conservation and Scientific Analysis of Painting, Van Nostrand Reinhold Company, New York.
Jirat-Wasiutynski, T (ed.) 1986, ‘Visual Examination’, Paper Conservation Catalogue, Book and Paper Group of the AIC, Washington.
King, H 2015, Fluorescent minerals, viewed 21 December 15, <http://geology.com/articles/fluorescent-minerals/>.
Lagorio, GM, Cordon, GB and Iriel, A 2015, ‘Reviewing the relevance of fluorescence in Biological systems’, Photochemical and Photobiological Sciences, vol.14, pp. 1538-1559.
Leclerc, F and Flieder, F 1992, ‘Influence of optical brighteners on paper permanence’, Manchester Conference Papers, The Institute of Paper Conservation, UK.
Messier, P, Baas, V, Tafilowski, D, Varga, L 2005, ‘Optical brightening agents in photographic paper’, Journal of the American Institute of Conservation, vol. 44 (1), pp. 1-12.
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Simpson-Grant, M. 2000b, ‘The Use of Ultraviolet Induced Visible-Fluorescence in the Examination of Museum Objects, Part 2’,Conserve-O-Gram 1/10, viewed 15 April 16, <https://www.nps.gov/museum/publications/conserveogram/01-10.pdf>.
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Authors:
Danielle Measday
Charlotte Walker
Briony Pemberton
Acknowledgements:
With our thanks to Lauren Ravi, Kendrie Richardson and Kerstin Wit for their research assistance, and to Briony Pemberton, Vanessa Kowalski and Libby Meltzer for sharing their personal observations.