Detail of Book of the Dead of Sobekmose, #37.1777E, transmitted light.

One method of examination we use is the use of transmitted light, which is light which passes through a transparent material from one side to the other.  Transmitted light is very useful in understanding how a sheet of papyrus is made and therefore, how it fits back together.

Use of the microscope is another instrument which makes our work easier.  Under magnification, and in combination with transmitted light, we can see clearly what we are doing and this makes our repairs and placing of loose fragments more precise.  It’s important to make as few and as small repairs as possible in order to stabilize the piece so that as much as possible of the original papyrus is visible.

Some of the clues we look for when reattaching fragments include looking at the contour of the fragment.  It’s shape is more easily visible with transmitted light, and we can see where the edges of the fragment may fit in place.  In transmitted light one can also easily see the vertical and horizontal lines of the papyrus plant’s fiber bundles (these bring water and nutrients up to the top of stalk) which create a characteristic crisscross pattern when viewing the sheet. The orientation of these lines on a fragment tell us in which orientation the fragment should be placed—horizontal or vertical, since all fibers on one side of a roll will be in the same direction.

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Most importantly with magnification and transmitted light we can use these lines to place fragments.  At every join, there is a “fingerprint” pattern of lines which tells us if the fragment fits there and if so, exactly where.  If all the fibers on that particular fragment do not line up perfectly, it does not fit.

To join fragments, or make repairs, we use a kozo-fibered Japanese paper which we tint with acrylics or watercolors to the color the papyrus so that the repairs are visible but blend in.

Toned Japanese paper mend

Wheat starch paste is used to adhere the mends to the papyrus.  The paper is cut into small rectangles with a scissors.  (Normally the Japanese paper is torn so that the strength of its fibers are utilized; here we do not want the Japanese paper fibers to pull on the papyrus fibers if we need to remove the mend.)  Wheat starch paste is used because it does not change the papyrus and is reversible over time.

Pasting up a piece of Japanese paper with wheat starch paste and a small brush.

After we place the mend on the papyrus, we place a blotter on top of it to dry it out and a small weight to keep it flat while drying.

See brass weight over white blotter.

As a comparison, these two photographs show how a fragment will fit in place, viewed in normal light.

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Sometimes we see mends to the papyrus that were made in ancient times.  We’ll talk more about those cases in the next blog.

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This post is part of a series by Conservators and Curators on papyrus and in particular theBook of the Dead of the Goldworker of Amun, Sebekmose, a 24 foot long papyrus in the Brooklyn Museum’s collection. This unique papyrus currently in 8 large sections has never been exhibited due to condition. Thanks to a generous grant from the Leon Levy Foundation, the entire papyrus is now undergoing conservation treatment. The conservation work is expected to last until fall 2011 when all 8 sections will be exhibited together for the first time in the Mummy Chamber. As each section is conserved, it will join those already on exhibition until eventually the public will see the Book of the Dead in its entirety.

Detail from the Book of the Dead of the Goldworker Amun, Sobekmose. New Kingdom, Dynasty 18, ca. 1479-1400 B.C.E. Ink and pigment on papyrus. Brooklyn Museum, Charles Edwin Wilbour Fund, 37.1777E.

For several reasons, it is a rare opportunity for us to test Museum objects using this technique. One necessary condition is that the object must fit into a certain time range. C-14 dating requires that the material in question be at least 2,000 years old (and up to 50,000 years old) to get a result with a significant certainty. Fortunately, we believed our papyrus fit into this time range.

Additionally, with works of art on paper, we do not often have an expendable sample for this type of analysis. Unlike the Fourier-Transform Infrared Spectroscopy and X-ray Fluorescence Spectroscopy described in the two previous posts which require no sample and were used to investigate pigments and adhesives used on the papyrus, C-14 dating requires a sample from the object, usually about 5 mg, which is destroyed during testing. After placing as many loose fragments as best as possible (we will talk more about our repairs in a future post), we had some very small ones remaining with no ink or coloring which were unplaceable. We consulted with our curators and decided that we could use a few of these small fragments for C-14 analysis.

Fragments circled are approximately 5 mg of sample.

There are only a handful of labs in this country that do this kind of analysis. We sent our sample to the Accelerator Mass Spectrometry (AMS) laboratory in the Physics Department at the University of Arizona in Tucson for analysis. C-14 dating was developed after World War II in the 1940s and 1950s and the principal is based on the measurement of the unstable carbon isotope 14C levels in a sample as compared to modern, known standards of the stable carbon isotopes 12C and 13C, which comprise the great majority of atmospheric carbon. (Isotopes are different forms of the same element.) The 14C atoms are produced when cosmic rays bombard the Earth’s upper atmosphere and produce nuclear reactions which produce neutrons. (About 2 atoms per second per centimeter squared are produced.) These neutrons react with nitrogen atoms to form 14C atoms, an unstable form of carbon. 14C mixes up into the atmosphere and is taken in by plants during photosynthesis, and other organisms as part of the food chain.

The 14C in an organism is always being replenished from the atmosphere at a constant rate while it is alive, and the ratio between it and the stable carbon isotopes is approximately constant with time. But when a plant or organism dies, its 14C intake stops and what remains will decay at a known rate (half life of 5,730 years). Therefore by measuring the amounts of the 14C and comparing it to known 12C data, an approximate age can be determined.

Spectra of C-14 results from University of Arizona AMS laboratory.

Our results are given in the spectra above. With some interpretation this shows that the results we received from the C- 14 method of scientific analysis are indeed consistent with our current understanding of our Book of the Dead, i.e. that it was produced in the New Kingdom, Dynasty 18, c. 1420 B.C.E.

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This post is part of a series by Conservators and Curators on papyrus and in particular the Book of the Dead of the Goldworker of Amun, Sebekmose, a 24 foot long papyrus in the Brooklyn Museum’s collection. This unique papyrus currently in 8 large sections has never been exhibited due to condition. Thanks to a generous grant from the Leon Levy Foundation, the entire papyrus is now undergoing conservation treatment. The conservation work is expected to last until fall 2011 when all 8 sections will be exhibited together for the first time in the Mummy Chamber. As each section is conserved, it will join those already on exhibition until eventually the public will see the Book of the Dead in its entirety.

As with the XRF analysis, we were able to perform FTIR using portable equipment belonging to Pratt Institute.  Eleonora del Federico, Associate Professor of Chemistry in the Math and Sciences Department at Pratt Institute brought her portable FTIR device to our paper conservation lab.

We decided to use FTIR for two reasons.  One is we want to know if the ancient Egyptians used an adhesive to attach separate sheets of papyrus to form a long continuous scroll.  We can see the joins where one sheet was attached to the next but it is unknown whether an adhesive was used to hold them together.  Note the dark vertical line towards the far left of this image of papyrus in transmitted light; this is where two sheets of papyrus have been joined together.

Two joins exist on this fragment, one towards the right side and one towards the left side of the piece. Samples were analyzed on areas of joins and non-joins in order to make a comparison.

Secondly, we want to try and identify the binder in the pigments used to write on and illustrate the Book of the Dead.

FTIR uses infrared radiation to observe the vibrational changes in chemical bonds in order to identify certain functional groups.  From this information, certain types of materials can be identified as protein-based, cellulose-based, etc. and this can help us to determine if an adhesive is present.

The FTIR device scans a tiny area over and over again to capture the vibrational changes.  Here you can see the FTIR scanner placed under the papyrus.  The infrared rays are directed upwards to scan the area to be analyzed.  For this analysis, each scan lasted around 5 hours, amounting to over 20,000 scans for each area.

Combined, the information from these scans provide data which is viewed in the form of spectra, with many bands that represent chemical bonding between two particular atoms or a group of atoms in a molecule. The spectrum will be compared to a set of known reference materials for identification and interpretation.

We think it is possible that the ancient Egyptians used an adhesive to join the individual sheets to form a roll.  If they did, it is likely that they used a protein-based adhesive such as animal glue, or a starch-based adhesive such as wheat starch paste.  It is also possible that no adhesive was used, and that moisture was used in the same way that it was used to join the strips to form a sheet (see previous blog entries on making papyrus).  In the latter case, moisture would be used along with extreme pressure to form a physical bond to join the sheets.  We also think that the binders used with the pigments on this scroll could likely be gum arabic or animal glue. We are still awaiting results for our analysis.

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This post is part of a series by Conservators and Curators on papyrus and in particular the Book of the Dead of the Goldworker of Amun, Sebekmose, a 24 foot long papyrus in the Brooklyn Museum’s collection. This unique papyrus currently in 8 large sections has never been exhibited due to condition. Thanks to a generous grant from the Leon Levy Foundation, the entire papyrus is now undergoing conservation treatment. The conservation work is expected to last until fall 2011 when all 8 sections will be exhibited together for the first time in the Mummy Chamber. As each section is conserved, it will join those already on exhibition until eventually the public will see the Book of the Dead in its entirety.

Fragment from Book of the Dead of the Goldworker of Amun, Sobekmose. Egypt, from Saqqara. New Kingdom, Dynasty 18, probably reign of Thutmose III to reign of Amunhotep II (circa 1479–1400 B.C.E.). Papyrus, ink, pigment, 14 x 288 2/3 in. (35.6 x 733.2 cm). Brooklyn Museum, Charles Edwin Wilbour Fund, 37.1777E

XRF is used to identify most elements with an atomic number on the periodic table equal to or greater than Aluminum.  Most importantly, the technique can be used without any harm to, or even contact with the art object.  For these reasons, art conservators use the technique to help them identify what elements are present in a targeted area of an object.

XRF uses x-rays to determine the area in question.  The spectra that are captured during each reading show peaks representing the x-ray’s energies for each element present.This image is an example of the spectra provided by XRF.  The characteristic peaks identify the elements and the height of the peaks can determine the quantity of each material present compared to other elements.

In the case of this papyrus scroll, we wanted to come to a better understanding of what inks the ancient Egyptian scribe used to write the spells for this Book of the Dead, and what pigments he used to illustrate it.

Fortunately for us, Eleonora del Federico, Associate Professor of Chemistry in the Math and Sciences Department at Pratt Institute, along with many of her students, also has a keen interest in studying papyrus and ancient Egyptian pigments.  Her department has a portable XRF device, which they brought to our paper lab on several occasions in order to perform the analysis with us.

This is what Pratt’s portable XRF device looks like.  Here is it seen mounted to a tripod and positioned just a few millimeters over the pigment we want to analyze.  When the device is turned on, x-rays are emitted from a tiny tube and directed towards the object.  These x-rays are capable of measuring an area just a few microns in diameter.

The first scan we did was on an area of red pigment in the vignette towards the right edge of the papyrus fragment (see arrow).

The XRF was positioned over the object and after a few minutes enough data was gathered for interpretation.

The results show a large peak of iron, which suggests that the pigment is an iron-based pigment such as red iron oxide.

We repeated this process several times in other areas on this fragment and the following pigments were indicated:

Red – red ochre
Yellow – yellow ochre
Green – malachite
Blue – Egyptian blue
Black – carbon black

These findings are consistent with the pigments that we know were available and often used by the Ancient Egyptians (see previous blog, Pigments and Inks Typically Used in Papyrus).

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This post is part of a series by Conservators and Curators on papyrus and in particular the Book of the Dead of the Goldworker of Amun, Sebekmose, a 24 foot long papyrus in the Brooklyn Museum’s collection. This unique papyrus currently in 8 large sections has never been exhibited due to condition. Thanks to a generous grant from the Leon Levy Foundation, the entire papyrus is now undergoing conservation treatment. The conservation work is expected to last until fall 2011 when all 8 sections will be exhibited together for the first time in the Mummy Chamber. As each section is conserved, it will join those already on exhibition until eventually the public will see the Book of the Dead in its entirety.

We typically use traditional photography to record images of artifacts in the visible light spectrum; this way we record on a digital file that which the human eye can see (fig.1). However, this technique can provide only a limited amount of information, since the visible portion of the electromagnetic spectrum is a very small portion (400-700nm) of the entire spectrum. By eliminating the visible light using barrier filters, we are able to record images that the unaided human eye could not detect. Generally, we record images in the near infrared  (700 to 900 nm) as well as the ultraviolet ranges (200- 400nm).

Fig.1 Fragment from the Book of the Dead of the Goldworker of Amun, Sobekmose. New Kingdom, Dynasty 18, ca. 1479-1400 B.C.E. Ink and pigment on papyrus. Brooklyn Museum, Charles Edwin Wilbour Fund, 37.1777E. Illuminated with visible light.

Infrared reflectography is often used in conservation to ‘see through’ paint layers that are impenetrable to the human eye and thus reveal underdrawings, underpaint, artist’s changes or pentimenti. Carbon black, one of the pigments used for chants and spells in our papyrus, is very absorbent of infrared radiation, which can help with deciphering inscriptions that have faded or been partly erased or even almost completely obliterated (e.g. charred documents).

It is now possible to capture high quality infrared images with a digital camera.  Infrared radiation generated by a light source such as a tungsten bulb falls on the subject, and then reflects off it on to the camera. With the help of an IR filter placed over the lens to block the visible light from passing through, a record of how the subject reflects the infrared radiation is created.

In our IR reflected photograph (fig. 2), the carbon black text on the papyrus fragment, heavily absorbs the infrared radiation and thus appears even more intense, while the iron oxide red pigment appears almost transparent as iron absorbs poorly in the infrared region.

Fig.2 Fragment from the Book of the Dead of the Goldworker Amun, Sobekmose. New Kingdom, Dynasty 18, ca. 1479-1400 B.C.E. Ink and pigment on papyrus. Brooklyn Museum, Charles Edwin Wilbour Fund, 37.1777E. Illuminated with infrared light.

Certain compounds can easily be detected under UV light, because they absorb this invisible (UV) energy and then re-emit it in visible light. Most UV examination lights, or black lights, emit wavelengths in the 350-360nm region (UVA). A UV filter is placed over the camera lens to block the visible light and exposing the ultraviolet sensitive sensor. This imaging methodology is called ultraviolet fluorescence (UVF). Natural resin varnishes, certain adhesives and pigments have their own characteristic fluorescence under UV light. UV radiation examination also provides information on materials which absorb and do not fluoresce, for example retouchings appear as dark patches on the varnish surface.

In our papyrus, the pigments did not exhibit characteristic fluorescence colors. They generally absorbed the UV radiation because they are metallic based and thus appeared dark. (fig. 3)

Fig. 3 Fragment from the Book of the Dead of the Goldworker Amun, Sobekmose; recto. Illuminated with ultraviolet light. The yellow ochre, red iron oxide and malachite (marked with corresponding colors) strongly absorb the UV light.

One of the most important questions we wanted to answer was whether an adhesive was used along the overlap of the papyrus sheets to form this papyrus roll. Viewing the verso of the papyrus under ultraviolet radiation, we noted an intense yellow- white fluorescence along the joins of the roll as well as in the location of old papyrus mends. This UVF suggests the presence of an adhesive, possibly a starch based one, used to join the sheets and make repairs (fig. 4). This was confirmed with a chemical spot test (Iodide Potassium Iodine) on a few samples of the fluorescing material. The strongly fluorescing areas were lightly swabbed with damp cotton, which turned black on the application of a small drop of 1% iodine solution.

Fig.4 Fragment from the Book of the Dead of the Goldworker Amun, Sobekmose; verso. Illuminated with ultraviolet light. The arrows indicate the joins (kolleses) whereas the triangle marks the area of old papyrus repairs performed after the scroll's manufacture and before the writing of the text.

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This post is part of a series by Conservators and Curators on papyrus and in particular the Book of the Dead of the Goldworker of Amun, Sebekmose, a 24 foot long papyrus in the Brooklyn Museum’s collection. This unique papyrus currently in 8 large sections has never been exhibited due to condition. Thanks to a generous grant from the Leon Levy Foundation, the entire papyrus is now undergoing conservation treatment. The conservation work is expected to last until fall 2011 when all 8 sections will be exhibited together for the first time in the Mummy Chamber. As each section is conserved, it will join those already on exhibition until eventually the public will see the Book of the Dead in its entirety.

The two most common pigments seen on papyri are black and red.  The black ink you see most often is used for writing the letters of the hieroglyphs or hieratic text and is almost always a carbon black ink.

Fragment from the Book of the Dead of the Goldworker Amun, Sobekmose.  New Kingdom, Dynasty 18, ca. 1479-1400 B.C.E.  Ink and pigment on papyrus.  Brooklyn Museum, Charles Edwin Wilbour Fund, 37.1777E.

The ink is made by burning organic materials such as wood or oil, and then pulverizing the material before mixing it with water.  To keep the particles from clumping together, the black is mixed with a binder, probably a plant gum from the Acacia tree family.  As a valuable source of timber in Egypt, its branches may have also been used as the source for the charcoal.  As well as keeping the carbon particles suspended in the water solution, the gum binder helps to keep the ink adhered to the papyrus surface.  This ink is very stable, does not fade, and does not deteriorate the papyrus below as some metallic inks can do.

Another predominant color seen on the papyrus is red, derived from the earth pigment iron oxide.  Like most pigments used in ancient Egypt it is made from a naturally-occurring mineral, rather than an organic material derived from living sources such as plants.  The mineral iron gives it its color.  The red was often used for rubrics such as titles and headings to distinguish them from the rest of the text.  In our Book of the Dead pictured above, they denote the beginning of spells.

The ancient Egyptians used reed brushes to write the text.  These brushes looked somewhat like brushes today and allowed the scribe to vary the thickness of the line.  They were held in a wooden (or sometimes ivory) palette which had a depression to hold the red and black inks.

Scribe’s Palette with 4 Reeds in a pen holder, #37.450E, Brooklyn Museum.

Later on in the Ptolemaic period, reed pens were used.

Wooden Board with Five Scribe’s Pens attached and Bound Together with a Small Piece of Linen, #37.451E, Brooklyn Museum.

The basic palette used to paint the vignettes, or illustrations, comprised a range of pigments either mined from the earth or extracted from minerals, including blue, green, black, white, red and yellow.   It is interesting to see that the vignettes are often painted in one color within an outlined area, rather than layered to create highlights or shading.

 In addition to naturally-occurring pigments, the ancient Egyptians are credited with making the first artificially made pigment, Egyptian Blue.

Detail and photomicrograph of Egyptian blue pigment, 2.7X magnification

Egyptian blue is a glass-like pigment which was made by heating together quartz sand, copper, calcium oxide, and an alkali such as natron, which was found naturally in the waters of Egypt.  This crystalline material is then ground into a pigment and is often referred to as blue “frit”.  It was often thickly applied and coarsely ground, visible under magnification, due to the fact that it appears paler the more it is ground.  The presence of Egyptian blue in our vignettes is indicated by recent analysis with x-ray fluorescence (see future blog post for more information on analysis).

On our papyrus, we see a green called malachite, a mineral pigment composed of copper carbonate.  This green was probably also used as a source of copper for Egyptian Blue mentioned above.

Detail and photomicrograph of mineral green pigment, probably malachite, 2.7X magnification

Interestingly the blues and greens on this papyrus have darkened over time and look almost black to the naked eye, but when viewed under magnification blue and green particles are visible, indicative of what these pigments originally looked liked.

The Egyptians also created an artificial green pigment, called a green frit, very similar in ingredients and manufacture to Egyptian blue.  Other green mineral pigments have been found on ancient Egyptian materials, including copper chlorides also familiar as the bright bluish green corrosion products seen on bronze metals, as well as mixtures of Egyptian blue with yellows to create greens.

The most common yellow found on Egyptian materials is a yellow ochre which is seen in the disc above the falcon and other yellow areas.  It is colored by iron-containing minerals and contains clay and silica.

Photomicrograph of yellow and red area below falcon’s eye, 1.6X magnification

It can be difficult to identify the pigments with certainty due to several factors including the difficulty in obtaining a viable sample and also changes in the pigments over time.  A description of our analysis of the pigments will be described in upcoming blog entries.

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This post is part of a series by Conservators and Curators on papyrus and in particular the Book of the Dead of the Goldworker of Amun, Sebekmose, a 24 foot long papyrus in the Brooklyn Museum’s collection. This unique papyrus currently in 8 large sections has never been exhibited due to condition. Thanks to a generous grant from the Leon Levy Foundation, the entire papyrus is now undergoing conservation treatment. The conservation work is expected to last until fall 2011 when all 8 sections will be exhibited together for the first time in the Mummy Chamber. As each section is conserved, it will join those already on exhibition until eventually the public will see the Book of the Dead in its entirety.

To make the roll, individual sheets were overlapped slightly; normally the sheet on the right overlapped the sheet on the left by 1-2 cm. The overlap was pasted, pressed and possibly burnished. Recent analysis has identified starch paste in the joins of several ancient papyri. Twenty sheets was the standard roll.

The completed roll or book was then rolled with the horizontal fibers on the inside and the vertical ones on the outside. If rolled in the opposite direction (vertical fibers inside) the fibers would have been crushed. The roll format explains why a laminate structure of perpendicular fibers was necessary. The rolls were stored either upright in vertical containers or in chests.

The height of the rolls varied in different periods. From ~2700-2200 BCE the maximum height was between ~8 and 9 ½”; while in the New Kingdom period ~1500-1100 BCE the average height was ~16″.

All types of recorded information were written on papyrus rolls or sections of a roll including legal, medical, administrative, mathematical and personal documents. In the 18^th dynasty (~1400 BCE) funerary texts began being copied onto papyri rolls and placed in wealthy burials; these became known as Books of the Dead.  These books usually read right to left and are unrolled from right to left.

The Book of the Dead of the Goldworker of Amun, Sebekmose a New Kingdom papyrus dating 1430-1400  measures 14″ in height and consists of 18 joined full sheets (each~16″ in width) and one partial sheet. The joins are easily identified in transmitted light as darker vertical lines due to the added opacity caused by the overlap.

One of the most unusual features of this Book of the Dead is that it is written on both sides of the papyrus. Normally scribes would avoid the vertical fiber side (verso) because it formed the outside of the roll and received the most wear, while the horizontal fiber side (called the recto) was better protected being on the inside.  As expected the spells and chants begin on the recto side. They are written in vertical columns in hieroglyphs and read correctly from right to left. The final spell, on the far left of the roll is completed just past the join of the 18th and 19^th sheet (the area represented by the black parallel lines in this image).

Note the last hieroglyph does not reach the bottom of the last column. The scribe has completed his work and does not need the extra 1 ½ sheets, thus explaining why there are 18 ½, rather than 20, sheets in this roll.

For whatever reason, and we are not sure why, after cutting off the rest of the roll the same scribe then flipped the roll horizontally and began writing on the verso in hieratic, a cursive form of hieroglyphs.

Note he begin the script just to the left of the last join which appears slightly lighter in color on the verso. The hieratic spells cover approximately 2/3 of the verso of the papyrus.

Treatment and analysis of this rare Book of the Dead is ongoing and as scientists, conservators, curators and modern papyrus makers continue their research the secrets of ancient Egyptian papyrus will also continue to unfold.

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This post is part of a series by Conservators and Curators on papyrus and in particular the Book of the Dead of the Goldworker of Amun, Sebekmose, a 24 foot long papyrus in the Brooklyn Museum’s collection. This unique papyrus currently in 8 large sections has never been exhibited due to condition. Thanks to a generous grant from the Leon Levy Foundation, the entire papyrus is now undergoing conservation treatment. The conservation work is expected to last until fall 2011 when all 8 sections will be exhibited together for the first time in the Mummy Chamber. As each section is conserved, it will join those already on exhibition until eventually the public will see the Book of the Dead in its entirety.

Papyrus is a perennial freshwater plant which favors marshes and swamps.  It grows best in shallow water along the edges of sheltered fresh water bodies, which is why the banks of the Nile are an ideal location for growing papyrus.  Fortunately, we are located next door to the Brooklyn Botanic Garden, where papyrus grows in the Aquatic House. 

We contacted the garden and they agreed to let us have a few stalks. Medium-sized stalks were selected for their uniform age and size and they were cut just above the bottom.  We brought the stalks back to the paper lab and cut them down further using a simple kitchen knife.  We decided to use the middle portion of the stalk to ensure consistency in thickness and in length.

We peeled away the green rind using a simple, small sharp knife blade.

We tried a variety of tools to thinly slice the stalks into strips including small sharp razor blades, and various kitchen utensils such as vegetable peelers and food slicers.  We found that a simple blade was the best tool to achieve the thinnest strips.  We sliced through each stalk using the parallel cutting method.

We did encounter some difficulty in slicing the strips as thinly as we wanted, and achieving uniform thinness among all of the strips.  This may be due to our skill level in slicing, the tools available to us, or with these particular stalks of the papyrus.

The strips were soaked in water for 24 hours to swell the plant cells and fibers and allow water to fill the air spaces.  This image shows them soaking in a tray of water, weighted down under a sheet of Plexiglas and some small brass weights to ensure that the strips remained submerged.

The wet strips were removed from the water bath.  We used a standard rolling pin to forcefully press the strips flat.  At this point we observed a significant reduction in the thickness of the strips.

We returned the flattened strips to the water bath, and the process of soaking and pressing the strips was repeated several times over the course of a few days.  At this point the damp, flattened strips were lined up side by side with the long edges of each strip slightly overlapping the next.

A second layer of strips was lined up side by side, on top of and perpendicular to the first layer, forming a two-layered sheet.

For a final press using extreme pressure, this sheet was placed into a wooden book press between sheets of blotter paper and flat wooden boards.  It was left in the press for several days, switching the blotters several times, to ensure that the sheet was fully dried and completely flat.  As described in Toni’s post, this extreme pressure causes any remaining hollow spaces and air ducts to compress and the plant fibers to interlock forming a very strong physical join.

After several days, the sheet was removed from the press.  Our final product was dry and flat yet flexible, and the layers were well-joined.

Its appearance differs from that of ancient papyrus in many ways.  The white color is the most notable difference; however it is believed that the color is similar to that of an un-aged sheet of ancient papyrus.  Our sheet is also much thicker than most examples of ancient papyrus, perhaps owing to our method of slicing or pressing the strips.

Samples of ancient and modern papyrus have been examined by researchers using extremely high magnification called Scanning Electron Microscopy (SEM) and these comparisons show a difference in the overall order, regularity and size of the plant cells.  In the samples of ancient papyrus, the cells demonstrated a very regular pattern similar to chain mail, and in the samples of modern papyrus, these cells exhibit a similar order and regularity, but differ in cell size.

Both visual and microscopic differences such as these serve as a reminder that duplicating the methods and tools used by ancient Egyptians is a challenge.  Trying to make papyrus ourselves gave us a much better idea of the structure of a sheet of papyrus and how it was done in ancient times, though all of the details to papyrus-making remain a mystery.

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This post is part of a series by Conservators and Curators on papyrus and in particular the Book of the Dead of the Goldworker of Amun, Sebekmose, a 24 foot long papyrus in the Brooklyn Museum’s collection. This unique papyrus currently in 8 large sections has never been exhibited due to condition. Thanks to a generous grant from the Leon Levy Foundation, the entire papyrus is now undergoing conservation treatment. The conservation work is expected to last until fall 2011 when all 8 sections will be exhibited together for the first time in the Mummy Chamber. As each section is conserved, it will join those already on exhibition until eventually the public will see the Book of the Dead in its entirety.

Pictorial displays in tomb murals and carvings never reveal the process of sheet formation, though often depict the papyrus plant. Only one document by Pliny the Elder, Natural History, XIII, written in the 1^st c. A.D.  attempts to describe the process of papyrus making. Unfortunately, this description is ambiguous and so lacking in details it has led many to believe Pliny never actually saw the process first hand. By the 10^th c. AD papyrus making becomes extinct and the secret of its fabrication appeared to be lost.

Papyrus is made from the sedge plant, Cyperus papyrus which grows in shallow water and was so abundant in ancient Egypt it was the source not only for the manufacture of flexible writing supports but for many everyday items such as shoes, coverings, boats, and food.  Ironically, by the 20^th century this plant no longer existed in Egypt though it has since been imported and cultivated. We don’t know whether the ancient Egyptians used wild or cultivated Cyperus papyrus plants of which there are many sub-species. Any one of these sub-species could have affected the quality and finish of a papyrus sheet. Nor do we know the tools and equipment which might have been used by the workshops producing the papyrus sheets. Thanks in large part to scientific analysis, conservation examinations and modern attempts at papyrus making by researchers, curators and conservators we have unlocked some of the basic secrets ancient Egyptian papyrus making.

The Egyptians cut the triangular green stalk close to the waterline and eliminated the flowering head.

When the outer green rind is removed a soft white triangular pith is exposed (above).  The pith was cut into strips either along the triangular faces of the stalk or straight through the triangle. At times the pith was unwrapped down to its core (below).

Scanning electron microscopy (extremely high magnification) can distinguish between the strip or peel method and indicates that both were used in antiquity. The strips or peeled papyrus were soaked in water to swell the fibers and cells. While wet the white pith yellows and darkens. Individual strips were laid upon a smooth surface, side by side and slightly overlapping. Then a second set of strips were laid onto the first, perpendicular to it. The two layered sheet is then hammered, rolled or beaten flat and then pressed while still moist. If the pith was peeled, two layers with fibers perpendicular to each other were pressed together.

The Egyptians always made papyrus sheets with this two layered laminate structure easily identified in transmitted light by a characteristic grid pattern. The criss-cross dark lines are the fiber bundles which run parallel to the stalk and which transported water and nutrients. Because of the perpendicular laminate structure, the fibers run horizontally on one side and vertically on the opposite side. The fibers give the sheet its strength. The lighter material in between the dark lines are the plant (parenchyma) cells also called the ground tissue they fill and give body to the framework.

There is still debate over whether the Egyptians added a glueing agent to adhere the two perpendicular layers of papyrus together. It is possible they did so in certain periods and not in others. Analysis and a variety of modern experiments repeatedly show that papyrus could have been made without any extraneous adhesive. The explanation for adhesion of the two layers to form a sheet is a physical and mechanical one. The parenchyma cells or ground tissue are stacked in a honeycomb like network running the length of the stem. These cells (red arrow) surround large hollow air ducts (green arrow) and look like this at very high magnification.

When  pressure is applied to overlapping strips of papyrus and to the perpendicular layers (press, rolling, hammering etc) the air ducts collapse causing the plant cells to merge into each other filling the hollow spaces and forming a dove-tail like join. Upon drying the merged cells lock causing complete and long term adherence between the layers and creating a sheet of papyrus.

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This post is part of a series by Conservators and Curators on papyrus and in particular the Book of the Dead of the Goldworker of Amun, Sebekmose, a 24 foot long papyrus in the Brooklyn Museum’s collection. This unique papyrus currently in 8 large sections has never been exhibited due to condition. Thanks to a generous grant from the Leon Levy Foundation, the entire papyrus is now undergoing conservation treatment. The conservation work is expected to last until fall 2011 when all 8 sections will be exhibited together for the first time in the Mummy Chamber. As each section is conserved, it will join those already on exhibition until eventually the public will see the Book of the Dead in its entirety.