Johanna Klügl | Bern University of the Arts (original) (raw)

Papers by Johanna Klügl

Research paper thumbnail of Fell, Holz und Bast – Neue Eisfunde aus dem 5. Jahrtausend v. Chr. vom Schnidejoch (Kanton BE, Schweiz).

Aufgetau(ch)t – Archäologie zu Seeufersiedlungen, Eisfunden und Klimawandel. Festschrift für Albert Hafner zum 65. Geburtstag, 2024

Im Beitrag werden erstmalig die Neuentdeckungen des 2020 komplett abgeschmolzenen unteren Eisfeld... more Im Beitrag werden erstmalig die Neuentdeckungen des 2020 komplett abgeschmolzenen unteren Eisfelds vom Schnidejoch vorgestellt. Es handelt sich um Pfeilfragmente, ein Fellfragment, einen Bastbeutel, ein Ensemble aus bearbeiteten Hölzern und Bastschnüren sowie weitere Holzfunde. Alle Objekte konnten mittels Radiokarbondatierung ins 5. Jahrtausend v. Chr., nämlich in den Zeitraum von 4800 bis 4200 v. Chr., datiert werden. Aus Gründen der Vollständigkeit werden die Neufunde zusammen mit den wenigen zeitgleichen, bereits 2015 publizierten Funden vorgestellt. Ausserdem wird die Erstversorgung und Bergung der vergänglichen feuchten oder gefrorenen Funde im alpinen Kontext erläutert und die kurativen Massnahmen vorgestellt, die nötig sind, um die Objekte in einen trockenen und stabilen Zustand zu überführen. Das Ziel ist, eine langfristige Erhaltung, Zugänglichkeit und Auswertbarkeit sicherzustellen. Die einmaligen Ausrüstungsgegenstände mit Funktionen wie Schutz, Aufbewahrung/ Tragen und möglicherweise Bekleidung belegen eindrücklich, dass bereits im 5. Jahrtausend v. Chr. das Schnidejoch regelmässig begangen wurde sowie, dass diese Nutzung nach aktuellem Wissenstand mutmasslich im Zusammenhang mit saisonaler Weidewirtschaft stand. Résumé Cet article présente pour la première fois les nouvelles découvertes faites dans le champ de glace inférieur du Schnidejoch, qui a complètement fondu en 2020. Il s'agit de fragments de flèches, d'un morceau de fourrure, d'un récipient en vannerie, d'un ensemble en bois travaillé et cordelettes en fibres végétales, ainsi que d'autres éléments en bois. Tous les objets ont pu être datés par radiocarbone au 5 e millénaire, soit entre 4800 et 4200 av. J.-C. Par soucis d'exhaustivité, ces nouvelles découvertes sont présentées en même temps que les quelques trouvailles déjà publiées en 2015. En outre, les étapes de prélèvement et de conditionnement de ce mobilier fragile, humide ou gelé dans le contexte alpin sont expliquées tout comme les mesures curatives nécessaires pour amener les objets à un

Research paper thumbnail of The interaction of water with archaeological and ethnographic birch bark and its effects on swelling, shrinkage and deformations

Heritage Science, Jan 7, 2021

Research paper thumbnail of Maximum moisture content of contemporary birch bark

Research paper thumbnail of Atlas of Micromorphological Degradation of Archaeological Birch Bark

Applied sciences, Sep 18, 2021

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Research paper thumbnail of On the rolling and plasticization of birch bark

Freshly harvested outer birch bark is a pliable, leather-like material, but within a short period... more Freshly harvested outer birch bark is a pliable, leather-like material, but within a short period it loses flexibility and becomes rigid. Further, still during the removal from the tree, it starts to roll back upon itself with the inner side out. This is relevant to conservators as objects made of birch bark do often show this type of deformation and need to be re-shaped. In this paper methods used nowadays by craftspeople to avoid the rolling of the outer birch bark (phellem) and flexibilization methods used by both craftspeople and conservators are reviewed. Some of these methods like the use of solvent vapours have some major drawbacks as birch bark contains a high amount of soluble substances within the cell lumen that can be solubilized during the treatment. In order to optimize treatment procedures for birch bark artefacts in the future it is important to understand the rolling of birch bark. We provide for the first time an explanation of the rolling pattern based on the microscopical analysis of the phellem cell dimensions on 3 to 6 years old twigs of Betula pendula and mature barks. The cell size and number measurements showed that the tangential cell length in the outer phellem layer is larger than in the inner layers while their number is lower. The combination of these two factors lead to the rolling of the bark with the inner side out once the inner tension is released upon the removal from the tree

Research paper thumbnail of Additional file 9 of The interaction of water with archaeological and ethnographic birch bark and its effects on swelling, shrinkage and deformations

Additional file 9: Outer side of C samples dry (above), humidified (middle) and after drying (bel... more Additional file 9: Outer side of C samples dry (above), humidified (middle) and after drying (below).

Research paper thumbnail of Additional file 7 of The interaction of water with archaeological and ethnographic birch bark and its effects on swelling, shrinkage and deformations

Additional file 7: Outer side of B samples in waterlogged condition (above) and after drying (bel... more Additional file 7: Outer side of B samples in waterlogged condition (above) and after drying (below).

Research paper thumbnail of Additional file 1 of The interaction of water with archaeological and ethnographic birch bark and its effects on swelling, shrinkage and deformations

Additional file 1: Full scanning isotherms of contemporary samples, retaining the phloem and with... more Additional file 1: Full scanning isotherms of contemporary samples, retaining the phloem and with or without lenticels.

Research paper thumbnail of Additional file 6 of The interaction of water with archaeological and ethnographic birch bark and its effects on swelling, shrinkage and deformations

Additional file 6: Video of time-lapse photography investigation showing the deformation of one s... more Additional file 6: Video of time-lapse photography investigation showing the deformation of one sample from material C during desorption.

Research paper thumbnail of Additional file 5 of The interaction of water with archaeological and ethnographic birch bark and its effects on swelling, shrinkage and deformations

Additional file 5: Lateral view of C samples dry (above), humidified (middle) and after drying (b... more Additional file 5: Lateral view of C samples dry (above), humidified (middle) and after drying (below).

Research paper thumbnail of Additional file 3 of The interaction of water with archaeological and ethnographic birch bark and its effects on swelling, shrinkage and deformations

Additional file 3: Lateral view of B samples in waterlogged condition (above) and after drying (b... more Additional file 3: Lateral view of B samples in waterlogged condition (above) and after drying (below).

Research paper thumbnail of Additional file 4 of The interaction of water with archaeological and ethnographic birch bark and its effects on swelling, shrinkage and deformations

Additional file 4: Lateral view of P samples dry (above), humidified (middle) and after drying (b... more Additional file 4: Lateral view of P samples dry (above), humidified (middle) and after drying (below).

Research paper thumbnail of Additional file 2 of The interaction of water with archaeological and ethnographic birch bark and its effects on swelling, shrinkage and deformations

Additional file 2: Full scanning isotherms of archaeological birch barks excavated from different... more Additional file 2: Full scanning isotherms of archaeological birch barks excavated from different contexts.

Research paper thumbnail of Additional file 8 of The interaction of water with archaeological and ethnographic birch bark and its effects on swelling, shrinkage and deformations

Additional file 8: Outer side of P samples dry (above), humidified (middle) and after drying (bel... more Additional file 8: Outer side of P samples dry (above), humidified (middle) and after drying (below).

Research paper thumbnail of Neolithic and Bronze Age archery equipment from alpine ice-patches: A review on components, construction techniques and functionality

The alpine ice-patch sites of Tisenjoch (I), Schnidejoch and Loetschenpass (CH) brought to light ... more The alpine ice-patch sites of Tisenjoch (I), Schnidejoch and Loetschenpass (CH) brought to light the most complete archery equipment known from European Prehistory. From the end of the last glaciation until the Middle Ages, bows and arrows were the most important weapons for hunting and warfare. The first verified artefacts of archery equipment are the arrows from Stellmoor, Northern Germany, which date to 10,000 BC, while the oldest bows found so far are still the two elm bows from Holmegard in Southern Denmark, dated to ca. 8000 – 6500 BC (Junkmanns 2013). During the Neolithic, bows were made almost exclusively from yew wood (Taxus baccata). Despite their different shapes, all prehistoric bows found in Europe are simple man-tall bows made from a single piece of wood with a more or less D-shaped cross-section and a flat belly side. Arrows were made from split wood or thin saplings and equipped with different types of points made from stone, bone/ antler material or the wood itself,...

Research paper thumbnail of Schnidejoch und Lötschenpass. Archäologische Forschungen in den Berner Alpen. Schnidejoch et Lötschenpass. Investigations archéologiques dans les Alpes bernoises. Bände/Volumes 1/2

Archaologie in den Hochalpen: Vom Ruckgang der Gletscher sind auch archaologische Objekte betroff... more Archaologie in den Hochalpen: Vom Ruckgang der Gletscher sind auch archaologische Objekte betroffen. Uber Jahrtausende hinweg haben sie im Eis uberdauert, nun kommen sie zum Vorschein. Im Hitzesommer 2003 fand eine Wanderin am Schnidejoch ein fremdartiges Objekt aus Birkenrinde. Es erwies sich als Teil eines 4800 Jahre alten Bogenfutterals. In den Jahren 2004 bis 2011 unternahm der Archaologische Dienst des Kantons Bern uber 30 Begehungen der Nordseite und – zusammen mit der Walliser Kantonsarchaologie – auch der Sudseite des Schnidejochs. Zahlreiche weitere Funde aus Holz, Leder und Metall konnten geborgen und wissenschaftlich untersucht werden. Einzigartige Funde Zu den spektakularsten Funden vom Schnidejoch zahlt das Bogenfutteral aus Birkenrinde. Weiter stechen aus den rund 900 Funden ein Pfeilbogen, mehrere vollstandige Pfeile und Fragmente einer Schale aus Ulmenholz hervor. Es handelt sich dabei um das alteste Holzgefass der Schweiz. Weitere herausragende Funde sind ein bronze...

Research paper thumbnail of The interaction of water with archaeological and ethnographic birch bark and its effects on swelling, shrinkage and deformations

Heritage Science, 2021

The aim of this study is to gain specific information on the water vapour interaction with archae... more The aim of this study is to gain specific information on the water vapour interaction with archaeological and ethnographic birch bark. Water is involved in a number of curative and preventive conservation measurements e.g. when re-shaping or drying objects and when defining climate directives for long-term storage. We measured the sorption isotherm of archaeological, ethnographic and contemporary birch bark at different temperatures and analysed the moisture-induced size and shape changes (swelling, shrinkage, deformation) during humidification and drying. The analysis revealed that, compared to other organic materials like wood, the moisture uptake of outer birch bark is modest. This can be attributed to the cell structure and composition: outer birch bark is composed of closed cells made to a large extent of hydrophobic components (suberin, lignin). The equilibrium moisture content is higher if lenticels or inner bark are present. The extent of brittleness and delamination of the ...

Research paper thumbnail of Schnydejoch - Objekte aus Holz und Rinde

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific r... more HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés. Schnydejoch Objekte aus Holz und Rinde A. Hafner, Johanna Klügl, Jehanne Affolter

Research paper thumbnail of On the rolling and plasticization of birch bark

Klügl, Johanna; Hafner, Albert; Di Pietro, Giovanna (2019). On the rolling and plasticization of birch bark (Submitted). In: 14th ICOM-CC Wet Organic Archaeological Materials (WOAM) Working Group Conference. Portsmouth, UK. Monday 20th – Friday 24th May 2019., 2019

Freshly harvested outer birch bark is a pliable, leather-like material, but within a short period... more Freshly harvested outer birch bark is a pliable, leather-like material, but within a short period it loses flexibility and becomes rigid. Further, still during the removal from the tree, it starts to roll back upon itself with the inner side out. This is relevant to conservators as objects made of birch bark do often show this type of deformation and need to be re-shaped. In this paper methods used nowadays by craftspeople to avoid the rolling of the outer birch bark (phellem) and flexibilization methods used by both craftspeople and conservators are reviewed. Some of these methods like the use of solvent vapours have some major drawbacks as birch bark contains a high amount of soluble substances within the cell lumen that can be solubilized during the treatment. In order to optimize treatment procedures for birch bark artefacts in the future it is important to understand the rolling of birch bark. We provide for the first time an explanation of the rolling pattern based on the microscopical analysis of the phellem cell dimensions on 3 to 6 years old twigs of Betula pendula and mature barks. The cell size and number measurements showed that the tangential cell length in the outer phellem layer is larger than in the inner layers while their number is lower. The combination of these two factors lead to the rolling of the bark with the inner side out once the inner tension is released upon the removal from the tree

Research paper thumbnail of Birch bark – the material and its processing with regard to the examination of the earliest known Neolithic bow case

During prehistory times birch bark was an easily available resource thanks to the widespread pres... more During prehistory times birch bark was an easily available resource thanks to the widespread presence of the birch tree in the natural landscape. Due to its perishable nature, archaeological objects made of birch bark like containers, hats, fishing equipment and torches are rare, but they do demonstrate the versatile uses of this material. Birch bark is water-repellent, lightweight, durable and can be worked similar to leather. Between 2003 and 2005 the earliest known protective case for a bow was recovered out of a melting ice patch at the Schnidejoch Pass in the Bernese Alps, Switzerland and represents a new example of the use of birch bark. The so-called bow case is made of differently oriented, superimposed birch bark strips, measures 1.7 m in lengths and is dated between 2880 and 2640 BC. This outstanding object – which lacks comparable parallels - was the focus of an interdisciplinary four years research project aiming to understand the choice of birch bark as construction mat...

Research paper thumbnail of Fell, Holz und Bast – Neue Eisfunde aus dem 5. Jahrtausend v. Chr. vom Schnidejoch (Kanton BE, Schweiz).

Aufgetau(ch)t – Archäologie zu Seeufersiedlungen, Eisfunden und Klimawandel. Festschrift für Albert Hafner zum 65. Geburtstag, 2024

Im Beitrag werden erstmalig die Neuentdeckungen des 2020 komplett abgeschmolzenen unteren Eisfeld... more Im Beitrag werden erstmalig die Neuentdeckungen des 2020 komplett abgeschmolzenen unteren Eisfelds vom Schnidejoch vorgestellt. Es handelt sich um Pfeilfragmente, ein Fellfragment, einen Bastbeutel, ein Ensemble aus bearbeiteten Hölzern und Bastschnüren sowie weitere Holzfunde. Alle Objekte konnten mittels Radiokarbondatierung ins 5. Jahrtausend v. Chr., nämlich in den Zeitraum von 4800 bis 4200 v. Chr., datiert werden. Aus Gründen der Vollständigkeit werden die Neufunde zusammen mit den wenigen zeitgleichen, bereits 2015 publizierten Funden vorgestellt. Ausserdem wird die Erstversorgung und Bergung der vergänglichen feuchten oder gefrorenen Funde im alpinen Kontext erläutert und die kurativen Massnahmen vorgestellt, die nötig sind, um die Objekte in einen trockenen und stabilen Zustand zu überführen. Das Ziel ist, eine langfristige Erhaltung, Zugänglichkeit und Auswertbarkeit sicherzustellen. Die einmaligen Ausrüstungsgegenstände mit Funktionen wie Schutz, Aufbewahrung/ Tragen und möglicherweise Bekleidung belegen eindrücklich, dass bereits im 5. Jahrtausend v. Chr. das Schnidejoch regelmässig begangen wurde sowie, dass diese Nutzung nach aktuellem Wissenstand mutmasslich im Zusammenhang mit saisonaler Weidewirtschaft stand. Résumé Cet article présente pour la première fois les nouvelles découvertes faites dans le champ de glace inférieur du Schnidejoch, qui a complètement fondu en 2020. Il s'agit de fragments de flèches, d'un morceau de fourrure, d'un récipient en vannerie, d'un ensemble en bois travaillé et cordelettes en fibres végétales, ainsi que d'autres éléments en bois. Tous les objets ont pu être datés par radiocarbone au 5 e millénaire, soit entre 4800 et 4200 av. J.-C. Par soucis d'exhaustivité, ces nouvelles découvertes sont présentées en même temps que les quelques trouvailles déjà publiées en 2015. En outre, les étapes de prélèvement et de conditionnement de ce mobilier fragile, humide ou gelé dans le contexte alpin sont expliquées tout comme les mesures curatives nécessaires pour amener les objets à un

Research paper thumbnail of The interaction of water with archaeological and ethnographic birch bark and its effects on swelling, shrinkage and deformations

Heritage Science, Jan 7, 2021

Research paper thumbnail of Maximum moisture content of contemporary birch bark

Research paper thumbnail of Atlas of Micromorphological Degradation of Archaeological Birch Bark

Applied sciences, Sep 18, 2021

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Research paper thumbnail of On the rolling and plasticization of birch bark

Freshly harvested outer birch bark is a pliable, leather-like material, but within a short period... more Freshly harvested outer birch bark is a pliable, leather-like material, but within a short period it loses flexibility and becomes rigid. Further, still during the removal from the tree, it starts to roll back upon itself with the inner side out. This is relevant to conservators as objects made of birch bark do often show this type of deformation and need to be re-shaped. In this paper methods used nowadays by craftspeople to avoid the rolling of the outer birch bark (phellem) and flexibilization methods used by both craftspeople and conservators are reviewed. Some of these methods like the use of solvent vapours have some major drawbacks as birch bark contains a high amount of soluble substances within the cell lumen that can be solubilized during the treatment. In order to optimize treatment procedures for birch bark artefacts in the future it is important to understand the rolling of birch bark. We provide for the first time an explanation of the rolling pattern based on the microscopical analysis of the phellem cell dimensions on 3 to 6 years old twigs of Betula pendula and mature barks. The cell size and number measurements showed that the tangential cell length in the outer phellem layer is larger than in the inner layers while their number is lower. The combination of these two factors lead to the rolling of the bark with the inner side out once the inner tension is released upon the removal from the tree

Research paper thumbnail of Additional file 9 of The interaction of water with archaeological and ethnographic birch bark and its effects on swelling, shrinkage and deformations

Additional file 9: Outer side of C samples dry (above), humidified (middle) and after drying (bel... more Additional file 9: Outer side of C samples dry (above), humidified (middle) and after drying (below).

Research paper thumbnail of Additional file 7 of The interaction of water with archaeological and ethnographic birch bark and its effects on swelling, shrinkage and deformations

Additional file 7: Outer side of B samples in waterlogged condition (above) and after drying (bel... more Additional file 7: Outer side of B samples in waterlogged condition (above) and after drying (below).

Research paper thumbnail of Additional file 1 of The interaction of water with archaeological and ethnographic birch bark and its effects on swelling, shrinkage and deformations

Additional file 1: Full scanning isotherms of contemporary samples, retaining the phloem and with... more Additional file 1: Full scanning isotherms of contemporary samples, retaining the phloem and with or without lenticels.

Research paper thumbnail of Additional file 6 of The interaction of water with archaeological and ethnographic birch bark and its effects on swelling, shrinkage and deformations

Additional file 6: Video of time-lapse photography investigation showing the deformation of one s... more Additional file 6: Video of time-lapse photography investigation showing the deformation of one sample from material C during desorption.

Research paper thumbnail of Additional file 5 of The interaction of water with archaeological and ethnographic birch bark and its effects on swelling, shrinkage and deformations

Additional file 5: Lateral view of C samples dry (above), humidified (middle) and after drying (b... more Additional file 5: Lateral view of C samples dry (above), humidified (middle) and after drying (below).

Research paper thumbnail of Additional file 3 of The interaction of water with archaeological and ethnographic birch bark and its effects on swelling, shrinkage and deformations

Additional file 3: Lateral view of B samples in waterlogged condition (above) and after drying (b... more Additional file 3: Lateral view of B samples in waterlogged condition (above) and after drying (below).

Research paper thumbnail of Additional file 4 of The interaction of water with archaeological and ethnographic birch bark and its effects on swelling, shrinkage and deformations

Additional file 4: Lateral view of P samples dry (above), humidified (middle) and after drying (b... more Additional file 4: Lateral view of P samples dry (above), humidified (middle) and after drying (below).

Research paper thumbnail of Additional file 2 of The interaction of water with archaeological and ethnographic birch bark and its effects on swelling, shrinkage and deformations

Additional file 2: Full scanning isotherms of archaeological birch barks excavated from different... more Additional file 2: Full scanning isotherms of archaeological birch barks excavated from different contexts.

Research paper thumbnail of Additional file 8 of The interaction of water with archaeological and ethnographic birch bark and its effects on swelling, shrinkage and deformations

Additional file 8: Outer side of P samples dry (above), humidified (middle) and after drying (bel... more Additional file 8: Outer side of P samples dry (above), humidified (middle) and after drying (below).

Research paper thumbnail of Neolithic and Bronze Age archery equipment from alpine ice-patches: A review on components, construction techniques and functionality

The alpine ice-patch sites of Tisenjoch (I), Schnidejoch and Loetschenpass (CH) brought to light ... more The alpine ice-patch sites of Tisenjoch (I), Schnidejoch and Loetschenpass (CH) brought to light the most complete archery equipment known from European Prehistory. From the end of the last glaciation until the Middle Ages, bows and arrows were the most important weapons for hunting and warfare. The first verified artefacts of archery equipment are the arrows from Stellmoor, Northern Germany, which date to 10,000 BC, while the oldest bows found so far are still the two elm bows from Holmegard in Southern Denmark, dated to ca. 8000 – 6500 BC (Junkmanns 2013). During the Neolithic, bows were made almost exclusively from yew wood (Taxus baccata). Despite their different shapes, all prehistoric bows found in Europe are simple man-tall bows made from a single piece of wood with a more or less D-shaped cross-section and a flat belly side. Arrows were made from split wood or thin saplings and equipped with different types of points made from stone, bone/ antler material or the wood itself,...

Research paper thumbnail of Schnidejoch und Lötschenpass. Archäologische Forschungen in den Berner Alpen. Schnidejoch et Lötschenpass. Investigations archéologiques dans les Alpes bernoises. Bände/Volumes 1/2

Archaologie in den Hochalpen: Vom Ruckgang der Gletscher sind auch archaologische Objekte betroff... more Archaologie in den Hochalpen: Vom Ruckgang der Gletscher sind auch archaologische Objekte betroffen. Uber Jahrtausende hinweg haben sie im Eis uberdauert, nun kommen sie zum Vorschein. Im Hitzesommer 2003 fand eine Wanderin am Schnidejoch ein fremdartiges Objekt aus Birkenrinde. Es erwies sich als Teil eines 4800 Jahre alten Bogenfutterals. In den Jahren 2004 bis 2011 unternahm der Archaologische Dienst des Kantons Bern uber 30 Begehungen der Nordseite und – zusammen mit der Walliser Kantonsarchaologie – auch der Sudseite des Schnidejochs. Zahlreiche weitere Funde aus Holz, Leder und Metall konnten geborgen und wissenschaftlich untersucht werden. Einzigartige Funde Zu den spektakularsten Funden vom Schnidejoch zahlt das Bogenfutteral aus Birkenrinde. Weiter stechen aus den rund 900 Funden ein Pfeilbogen, mehrere vollstandige Pfeile und Fragmente einer Schale aus Ulmenholz hervor. Es handelt sich dabei um das alteste Holzgefass der Schweiz. Weitere herausragende Funde sind ein bronze...

Research paper thumbnail of The interaction of water with archaeological and ethnographic birch bark and its effects on swelling, shrinkage and deformations

Heritage Science, 2021

The aim of this study is to gain specific information on the water vapour interaction with archae... more The aim of this study is to gain specific information on the water vapour interaction with archaeological and ethnographic birch bark. Water is involved in a number of curative and preventive conservation measurements e.g. when re-shaping or drying objects and when defining climate directives for long-term storage. We measured the sorption isotherm of archaeological, ethnographic and contemporary birch bark at different temperatures and analysed the moisture-induced size and shape changes (swelling, shrinkage, deformation) during humidification and drying. The analysis revealed that, compared to other organic materials like wood, the moisture uptake of outer birch bark is modest. This can be attributed to the cell structure and composition: outer birch bark is composed of closed cells made to a large extent of hydrophobic components (suberin, lignin). The equilibrium moisture content is higher if lenticels or inner bark are present. The extent of brittleness and delamination of the ...

Research paper thumbnail of Schnydejoch - Objekte aus Holz und Rinde

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific r... more HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés. Schnydejoch Objekte aus Holz und Rinde A. Hafner, Johanna Klügl, Jehanne Affolter

Research paper thumbnail of On the rolling and plasticization of birch bark

Klügl, Johanna; Hafner, Albert; Di Pietro, Giovanna (2019). On the rolling and plasticization of birch bark (Submitted). In: 14th ICOM-CC Wet Organic Archaeological Materials (WOAM) Working Group Conference. Portsmouth, UK. Monday 20th – Friday 24th May 2019., 2019

Freshly harvested outer birch bark is a pliable, leather-like material, but within a short period... more Freshly harvested outer birch bark is a pliable, leather-like material, but within a short period it loses flexibility and becomes rigid. Further, still during the removal from the tree, it starts to roll back upon itself with the inner side out. This is relevant to conservators as objects made of birch bark do often show this type of deformation and need to be re-shaped. In this paper methods used nowadays by craftspeople to avoid the rolling of the outer birch bark (phellem) and flexibilization methods used by both craftspeople and conservators are reviewed. Some of these methods like the use of solvent vapours have some major drawbacks as birch bark contains a high amount of soluble substances within the cell lumen that can be solubilized during the treatment. In order to optimize treatment procedures for birch bark artefacts in the future it is important to understand the rolling of birch bark. We provide for the first time an explanation of the rolling pattern based on the microscopical analysis of the phellem cell dimensions on 3 to 6 years old twigs of Betula pendula and mature barks. The cell size and number measurements showed that the tangential cell length in the outer phellem layer is larger than in the inner layers while their number is lower. The combination of these two factors lead to the rolling of the bark with the inner side out once the inner tension is released upon the removal from the tree

Research paper thumbnail of Birch bark – the material and its processing with regard to the examination of the earliest known Neolithic bow case

During prehistory times birch bark was an easily available resource thanks to the widespread pres... more During prehistory times birch bark was an easily available resource thanks to the widespread presence of the birch tree in the natural landscape. Due to its perishable nature, archaeological objects made of birch bark like containers, hats, fishing equipment and torches are rare, but they do demonstrate the versatile uses of this material. Birch bark is water-repellent, lightweight, durable and can be worked similar to leather. Between 2003 and 2005 the earliest known protective case for a bow was recovered out of a melting ice patch at the Schnidejoch Pass in the Bernese Alps, Switzerland and represents a new example of the use of birch bark. The so-called bow case is made of differently oriented, superimposed birch bark strips, measures 1.7 m in lengths and is dated between 2880 and 2640 BC. This outstanding object – which lacks comparable parallels - was the focus of an interdisciplinary four years research project aiming to understand the choice of birch bark as construction mat...