A summary of ultra-violet fluorescent materials relevant to Conservation

Publish date: 
14 Mar 2017
Author: 
Danielle Measday, Museums Victoria

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.

 Figure 1: The Electromagnetic Radiation Spectrum. Diagram: Danielle MeasdayObservation 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. 34951

 

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.

Gettens, R and Stout, G 2007, Painting Materials: A Short Encyclopaedia, Dover Publications, New York.

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.

Museum of Fine Arts, Boston, Cameo Materials Database, viewed 5 January 2016, <http://cameo.mfa.org/wiki/Madder>.

Mustalish, R A 2000, ‘Optical brighteners: history and technology’, Tradition and Innovation, Advances in Conservation, IIC Melbourne Congress, pp. 133-136.

Newton, R and Davison, S 1989, Conservation of Glass, Butterworth-Heinemann Ltd, Oxford, p. 192.

Pearlstein, E, Hughes, M, Mazurek, J, McGraw, K, Pesme, C, Garcia-Garibay, M 2014, ‘Correlations between photochemical damage and UV fluorescence of feathers’, Preprints of ICOM-CC 17th Triennial Conference, Melbourne.   

Purewal, VJ and Colston BJ 2014, ‘Novel detection and removal of hazardous biocide residues historically applied to Herbaria’, Poster presented at Society for the Preservation of Natural History Collections Annual meeting, National Museum of Wales, Cardiff.

Rivers, S and Umney, N 2013, Conservation of Furniture, Routledge, New York, pp. 388 and 610.

Simmons, J 1995, ‘Storage of Fluid Preserved Collections’, in Rose, CL, Hawks, C and Genoways, HH (eds.)  Storage of Natural History collection: A Preventive Conservation Approach, SPNCH, New York.  

Simpson-Grant, M. 2000a, ‘The Use of Ultraviolet Induced Visible-Fluorescence in the Examination of Museum Objects, Part I’,Conserve-O-Gram 1/09, viewed 15 April 16, < https://www.nps.gov/museum/publications/conserveogram/01-09.pdf>.

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>.

The Smithsonian Walter Reed Biosystematics Unit, n.d., Fluorescence in Scorpions, accessed 21 December 15, <http://www.wrbu.org/scorpions/sc_uv.html>.

Stuart, B 2007, Analytical Techniques in Materials Conservation, Wiley, Chichester.

Welsh, VL, Van Hooijdonk, E, Intrater, N, and Vigneron, J 2012, ‘Fluorescence in insects’, Proc. SPIE, Nat. Light: Light in Nat, IV.

Wilkins, A 1999, ‘Ultra violet light and its use with Fluorescent minerals’, The Fluorescent mineral society, viewed 21 December 15, <https://www.uvsystems.com/articles/uvlightandfluorescentminerals.pdf>.

Wilson, L 2014, To see the world in a grain of sand: a closer look at the ‘Melbourne Blakes’, viewed 19 January 16 <www.ngv.vic.gov.au/.../to-see-a-world-in-a-grain-of-sand-a-closer-look->.

World Health Organisation 2016, ‘Ultraviolet radiation’, viewed 2 December 16, <http://www.who.int/uv/en/>.

Zieske, F 2002, ‘Paul Cezanne’s Watercolours: His Choice of Pigments and Papers’, The Broad Spectrum, Archetype Publications, London.

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.