Stained wood The identification of natural and in wooden works of art

Achim Unger and Wibke Unger

IRG 41st Annual Meeting, Biarritz, France, 09 -13 May 2010 Dyestuffs from the nature and industry

Natural dyes Synthetic dyes

Dyes from Coal tar dyes plants Aniline dyes Azo dyes animals Anthraquinone dyes fungi Sulfur dyes Nitro and nitroso dyes

Rasped natural - colored Historic packaging for wood and roots methyl violet Dyestuffs of vegetable origin

Wood Old fustic, Brazil wood

Bark Black oak

Fruits Common buckthorn

Leaves Indigo plant

Roots Madder,

Flowers Safflower

Seed Annatto

Lichen Orchella weed Dyestuffs of animal origin

Insects Marine snails Cuttle fish

Kermes, Lac-insect, Sepia

Peter-Paul Rubens The dog of the Phoenician god Melqart discovers the spiny - murex Dyestuffs of fungal origin

„Mycodyes“ Pynoporus cinnabarinus Cinnabarin

Chlorociboria sp. Xylindein

Phanerochaete sanguinea Xylerythrines

Pulcherricium caeruleum Terphenols Classification of natural dyes based on the method

Natural dyes

Mordant dyes Direct dyes Vat dyes

Pre-treatment of fiber Dyeing of fiber Soaking of fiber mate- material with metal material without rial into a solution of the salts pre-treatment reduced dye. After removal from the vat oxidation to the real dye on the material

Examples Examples Examples

Alizarin Berberine Indigo Brazilin Carthamin Tyrian Carminic acid Curcumin Purple Analytical procedures for identification of dyes and mordants

Methods

Dyes Mordants

Non-destructive

UV/Vis spectrometry (UV/Vis) X-ray fluorescence 3D fluorescence spectrometry spectrometry (XRF)

Destructive

High-performance liquid Atomic emission spectrometry chromatography (HPLC) (AES)

Thin layer chromatography (TLC) Red-stained wood (I) Application of extracts from Brazil wood

Brazil wood (Caesalpinia sp.) Shutter cabinet, David Roentgen, 1773

Brazilin –absorption spectrum and formula Parquet flooring, Spindler Brothers, 1765 Red-stained wood (II) Application of extracts from Cochineal

American Cochineal (Dactylopius coccus) on the nopal cactus Toilet table, Abraham Roentgen, 1765

Rose intarsia stained with Carminic acid – cochineal extract absorption spectrum and formula Yellow-stained wood (I) Application of extracts from European barberry

European barberry (Berberis vulgaris) Augsburg cabinet, 1560/70

Barberry wood Maple intarsia yellow-stained with an extract from barberry wood Berberine –absorption spectrum and formula Yellow-stained wood (II) Application of extracts from Turmeric

Turmeric (Curcuma longa) „The Holy Rochus“, Wood paneling, Spindler marquetry painting, Brothers, 1765-68 Spindler Brothers, 1770

Reverse side of curcuma- stained intarsia Curcumin –absorption spectrum and formula Blue-stained wood (I) Application of Indigo (I)

Woad () Preliminary stage: Isatan B Distribution map of indigo species

Indigo plant (Indigofera tinctoria) Preliminary stage: Indican Blue-stained wood (II) Application of Indigo (II)

Woad Indigo plant

Leaves dried on

Woad mill in Thuringia, Germany, 1910

Indigo dye balls Woad ball Blue-stained wood (III) Application of Indigo (III)

Indican or Isatan B

Fermentation

Indoxyl (+ Glucose)

Air

Indigo

Indigo Leuco - Indigo Blue-stained wood (IV) Application of Indigo (IV)

Tyrolese cabinet , around 1630, Grassi-Museum Leipzig, Germany

Shavings stained with indigo Blue-stained wood (V) Application of Indigodisulfonic acid (Indigo carmine)

+Sulfuric acid

Indigodisulfonic acid, Indigo disodium salt (indigo carmine)

Indigo Retention time: 13.0 min

Retention Indigo carmine time: 4.0 min

Part of a table manufactured by D. Roentgen, 1778, Bavarian National Museum Munich Absorption spectra Green-stained wood (I) Application of Barberry extract + Indigo or Indigo carmine

Wood paneling, Spindler Brothers, 1772-73 The New Chambers Potsdam, Germany

Indigo

Berberine

Green-stained intarsia based on HPLC – Contour plot berberine and indigo carmine Green-stained wood (II) Utilization of wood infected by Chlorociboria sp.(I)

Hyphae of Chlorociboria sp. in wood secreting a green dye

„Xylothek“, Waldenburg, Germany, Xylindein –absoption spectrum and formula 18th century Green-stained wood (III) Utilization of wood infected by Chlorociboria sp.(II)

Wood paneling, Tyrol, 16th century

Intarsia painting, Antonio Violin, Black forest, Barili, San Quirico d‘ Orcia, Germany, 17th century Italy, 1502

Desk, Oslo, Norway, 18th century Grey-or brown-stained wood? Application of iron and nitric acid

Abraham Roentgen David Roentgen (1711-1793) (1743-1807)

Fe + HNO3 + Wood

18th century Today Overview of the identified dyes

Red dyes Blue dyes Brazilin Indigo Carminic acid Indigo carmine Santalin

Yellow dyes Green dyes Apigenin Xylindein Berberine Curcumin

Luteolin Brown dyes Morin Ellagic acid

Inner part of a table for sewing, after 1750, private property Searching for fungus-stained wood utilized for works of art

Chlorociboria sp. Fusarium sp. Ophiostoma sp. „Marble rot“

?

Tunbridge ware Modern wood paneling Medaillon, stained with Ulm cabinet, Ophiostoma sp. Germany,1580 Wibke and Achim Unger

Thank you for your attention

IRG 41st Annual Meeting, Biarritz, France, 09 -13 May 2010