The restoration of books is based on their characteristics. During the restoration process, the processing guidelines have several similarities with general printed documents, because their main body is paper. However, if the book itself is a work of art, such as a classic literary work, a rare treasure, a document with exquisite and special printing quality, historical significance, wonderful illustration art, or special binding skills, etc. and other factors, thus making books extremely precious. The biggest difference between book repair and general paper repair is that the function of a book is to be used. If it is damaged due to use, it must be restored to its original appearance as a book. A book is not a sketch or a painting that can be admired from a distance. Books are meant to be touched in the hand, allowing readers to enjoy the pleasure of flipping through and reading. When restorers face book restoration work, although it is also paper restoration, they still need to clearly distinguish the differences in damage. The problem with books is that damaged pages are less mobile when repairing them. This means that each piece of paper is sewn together, making repairs more difficult. However, when dealing with binding restoration, we also face other problems, namely the treatment of the materials used to bind books: such as leather, linen, cardboard, wood, parchment, etc. Restorers must be skilled in these materials to be able to do a good job of restoration. For binding restoration, the restorer should have knowledge of modern binding technology (art) in order to do a more accurate job of book restoration. Otherwise, it is best to consult an expert in binding and then the two of them work together to complete the work.
In order to discuss book restoration and binding restoration in detail, we will first discuss the content of the book, text or pattern, and then discuss issues such as cover or appearance. It can be divided into several parts: 1. Exploring the condition of the books first; 2. Commonly used book repair treatments; 3. Special treatments for binding.
First explore the condition of the books: This step is necessary and very important. The restorer needs to start with artistic knowledge and perspective in order to handle it correctly. First, summarize the situation of repairing books, list the order and methods of repair, try to understand the reasons for the damage of the works, and judge whether it may be biological damage, chemical changes, physical changes and other factors.
Generally used book repair and treatment methods, common damage and treatment:
*Common damage is caused by animal or insect erosion, such as rats, cockroaches, termites or other borers. Usually the damaged areas are arranged in a large area; there is also glue on the spine of the book, and moths also like to eat this area. In addition, cardboard or wooden board covers are also areas that moths like to attack. The treatment method is to first put a piece of formaldehyde agent in a sealed plastic bag to let it evaporate and kill insects; then dispose of the killed borers, eggs or larvae. It is necessary to pay attention to whether there are still borers alive in order to carry out the second insecticide treatment. Alternatively, the steam action of peritrina can be used. This treatment method must be done very carefully, because it is directly facing the book, and oil stains will be left if you are not careful. Pest control work must be carried out outside the studio location and cannot be carried out in clean areas that have been treated with insecticides. Make sure the books are completely insect-killed before placing them together with other books.
*In terms of biological erosion, the spine and cover areas are usually the most common, especially if the paper is wet, it is more likely to cause erosion. Most of the damage is caused by fading and brittleness of the paper. In addition, mold and bacteria will also leave dark black stains or yellowing on books. The treatment method can be as described above, using formaldehyde volatilization and sterilization. Although mixed ethylene oxide has a better sterilization effect, this method is highly toxic and dangerous and requires special treatment with expensive machines. The best way to clean is to work page by page, but this must be completely separated from uninfested books, as spores spread quite quickly. When conservators handle infected books, it is best to wear gloves, a hood to cover your hair, and a mask to protect your respiratory organs. People with allergies or respiratory problems should not do this type of work.
Surface dirt: This type of dirt is most common on the first stack of paper (paper stack) and the bottom stack of paper. If these areas are scattered or loose, they can be disassembled and cleaned and acid-base neutralized, but bleaching is not recommended because the color difference from the original book is too obvious. As for the stitching work, it is not complicated, and the processing effect of this part of the disassembly is quite good. If you cannot do the above treatment, you can only do machine or dry cleaning treatment. Place a wooden or plastic board behind the wiped paper and apply gentle pressure. This method is also very effective and can clean any oil, wax or stains caused by use. What is more difficult is the treatment of regional acidified spots. The results of treatment are usually unsatisfactory. If it can be separated and treated, it should be separated and treated. Dirt caused by long-term use usually penetrates the bottom layer of the paper, especially the corners. First clean it with a machine, then wet the blotting paper and put it on the back of the paper, then use a cotton ball or gauze to soak the methyl plant fiber. The methyl plant fiber must be as thick as gel, and then use a cotton ball or gauze to soak it in warm water. , then wipe the acidified spots with filter paper. You can also use fiber paper and methyl plant fiber to allow dirt to escape through capillary action, which can also prevent dirt from creeping and spreading on the paper. This method should be repeated every day, as moisture and leakage can easily deform the paper. Wrinkles occur when paper deforms.
*The smear caused by wax should first be removed with the tip of a scalpel, and then assisted by a solvent and a hot knife. However, filter paper needs to be placed on both sides of the paper, so that the residue of the wax will remain on the filter paper. The effect is good, but the process is relatively slow.
It is best to use blotting paper, Remay nylon or filter paper when handling. However, if the oil stain has been oxidized, dark brown stains will appear, especially in areas where the oxidation is particularly severe. The paper will be completely dull and black, or even cracked, and the paper substrate will be damaged. In this case, you may want to consider breaking the book apart, processing it page by page, and using calcium hydroxide to lighten the dark brown color of the paper. Cracked or damaged areas are grafted or fixed with Klucel. These treatments can lighten the color of the oil stain, but do not bleach, which will make the stain more fragile and cause acidic spots.
Lower, relative humidity is less than 50%. Heating is not allowed as it encourages the growth of microorganisms, but air-conditioning and ventilation are possible. If there is biological erosion, use volatilization to sterilize as mentioned above.
*If the soiling caused by moisture has been for a long time, the paper will deform and produce acid spots. This is not a problem if the book can be taken apart for cleaning. If it cannot be disassembled, you must first use absorbent paper to do local treatment, then use a spray gun to wet the acidified spots, and use methyl plant fiber to absorb dirt strongly. The effect of this treatment is only partial, but if it is disassembled and processed, additional damage will be more troublesome.
*Brown dirt on the surface of the paper: These dirt appear on the surface of the paper in the form of spots, commonly known as foxing. Most of these dirt are attached to the paper during the paper manufacturing process. loads or other materials. Some can be treated with acid-base neutralization. But generally you need to use bleach. Treat the area first and then wash the entire area. This method of processing is no problem for paintings, but for books, the pages must be opened. Books are often two or three hundred pages thick which is quite cumbersome. However, the restorer can also do spot bleaching, and use a spray gun to blur the less obvious spots.
* Burnt documents or metal pigment stains on the paper: Although the problems of burnt documents and metal pigment stains are different, the treatment methods are similar. Metallic pigment contamination is a ferrogalicas acidification problem and is a more serious situation that needs to be addressed immediately. What is certain is that some parts (that is, the written text) are damaged beyond repair. In the same situation, if it is a book that has suffered a disaster, the edges are irreversibly burnt. If a new substrate is used for grafting, the grafting often fails due to insufficient tension of the burnt paper. Repairs are handled according to the degree of damage. In fact, it is easier to deal with the burnt areas of books if they are on the edges or corners. Clean it first and remove the burnt parts. After acid removal and paper fixation, the effect is not satisfactory. It would be better if it is processed by machine again. But if it's a manuscript, the damage is to the text itself, and treatment of the burnt parts is impossible because we don't know what kind of writing technique it is. The available methods are cleaning and acid removal, the water level should not be too high, and protective measures should be taken. You can use Remay nylon or machine repair. The final method is to use polyethylene to make thin sheets and use rollers or paper rolls to roll them. Although it is not ideal, it can at least be used as a reference or to make a microfilm for a work that is almost destroyed.
* Damaged or loose: Any book can become damaged or loose, but there are some characteristics of books that provide us with some guidelines.
*Damage must be caused by damage to both sides of the paper. Which side should be grafted or sutured from? Use the most delicate and transparent fiber paper and Klucel or methyl plant fiber (depending on the solubility of the ink) ), in order not to damage the texture of the paper, try to stick the fiber paper on the text from the side with less text. Because the fiber paper is transparent, the text can naturally be seen. But remember never use thick paper for grafting. When disassembling and rebinding, be sure to measure the thickness of the paper. A folded piece of paper is the thickness of two pages, plus the thickness that may be added during processing - disassembling, cleaning, and acid removal will all increase the thickness - these additional thicknesses Each fold of origami must be slowly reduced in thickness through a press according to normal fabrication procedures before it can be bound.
*Placement of stacks of paper: When dealing with books that are damaged, have incomplete pages, or are lost, we usually use a paper repair table and draw the largest stack of papers on a transparent glass table. The edge and center of the page. If there are only four or more pages in a stack of paper, the edge of the outermost paper will be about 2mm longer. In this way, we can deduce the size ratio of the pages in the remaining stacks of paper, and then stitch them firmly to make the book's sections neat, because we do not use a cutting machine in this process (which will destroy the integrity of the book). In the binding of ancient books, the edges and spine grooves are relatively large, and the interlining pages can be seen.
*Acidification of books: This is the most common problem that all paper will encounter. But in books, it may be the problem itself. The paper will turn brown, emit a strong smell, or even crack and break. One solution is acid-base neutralization, but this still depends on the book. It is best to dismantle the binding, because in serious cases, in addition to acid removal, the scattered areas must be fixed or grafted. A compromise solution is to use barium hydroxide plus methanol, but care must be taken in the binding area.
Various methods of acid-base neutralization of paper have been discussed in Watercolor Restoration. Let’s discuss them below for book binding restoration.
Special treatment for binding
Data card: Record of general information, such as the time when it was sent for repair, the owner, the cost... etc. However, the processing of this type of data card is similar to that of all printing types, and is not as important as the archiving of artworks.
Book photography archive: Book photography is like taking a picture of the entire body, unlike a flat painting. Data records such as light intensity, focus, auxiliary light... and other factors need to be loaded. The parameters of each photo must be the same (aperture, speed, film... etc.).
Compilation of historical information on books: book binding technology and style, binding methods, decorative techniques, use of techniques (leather spine hardcover or all leather hardcover), sewing methods, and stitching materials of the era ...and so on, put these information together with the most original information from the original book. You should also pay attention to whether the cover is sewn or separated from the book, whether it is made of wood or cardboard, whether it has been stitched or protected by iron, whether it has metal corners, etc., as well as the book's end pages, etc., all of which need to be included in the repair. deal with. Also, ask the librarian about the book's collection seal and catalog label. Often after opening a book, we will find that the cardboard for the cover is made from waste paper from other badly printed books. This may be a lost book or a book that we don't even know about. This must also be included in the file. material.
Selection of materials: This point is not specifically about the restoration of bindings, but refers to how to choose the appropriate and correct materials for correct book restoration. Restorers need to understand the material application of modern binding technology. They must use acid-free neutral materials to avoid damaging the books. Restoration methods must strive to be restorable. They must respect the integrity and integrity of the work. They must not be damaged by repair or grafting. Highlight a certain part. The use of paper must also be neutral, such as gauze strips reinforced on the inside, interlining or grafting. It is best to use a material that will not stain, otherwise once it gets wet, the staining area will easily produce acidified spots.
* Wooden board covers are often damaged due to biological erosion. If they can still be preserved, they should be sterilized, fixed, and a hard board cover installed in the damaged area. If it cannot be repaired, we can redo it using the same material, usually oak. However, it is not easy to find materials that are as dry and stable as logs. Other alternative materials can be acrylic, but acrylic is more expensive and heavier than wooden boards, which will increase the weight of the book (if it is a small book, you can still consider using it). In addition, wooden plywood used in general ships can also be used, which is lighter in weight, strong in durability and not easy to deform. When the outer cutout of the cover becomes a round bald area, a wooden board needs to be used to make a hard cover at the corner. All new boards need to be bonded with acid-free cardboard on both sides to prevent wrinkles or damage.
*Leather products generally use sheepskin or calfskin, but it must be natural leather and cannot be processed or dyed. Tanned leather is preferably vegetable-based, which is easy to handle and dye. However, mineral dyeing must be avoided, as it can easily damage the leather. It's best to look for tanners with fine craftsmanship and experiment a bit to find out what quality works best. Ripe, tanned sheepskins are not ideal and are not easy to preserve.
*Alum-tanned pigskin can be used to bind ancient books. However, for leather products used in binding, French leather is the best in terms of dyeing quality and characteristics. The same goes for French parchment, binding or restoration is of the best quality, it's just expensive. Generally, most of the various types of parchment paper available on the market are hard and easily damaged, and are bleached with lime. Poor-quality parchment can be soaked in water and 50% ethanol to make it more elastic, and some of the white color can also be washed away. In addition, other materials such as gauze and stitching to strengthen the fixation should also be of good quality and be made of linen or hemp that is similar to the material of the original book. If the white color of the backing pages looks too abrupt with the original book, you can wash it with tea or coffee, and then fix it with Klucel and ethanol. Of course the best way is to use the most standard dye from the paper mill, which is also the dye used for machine repair.
*The traditional viscose used for binding includes rabbit glue and bone glue. However, this type of adhesive cannot be used during repairs because it easily solidifies and loses its stickiness. Its yellowish color will also stain books. In addition, the traditionally used glue is paste (flour plus water, or potato flour or corn flour plus water). You can buy it off the market, but add a few drops of phenol (test before use, because too strong a bactericidal effect will also produce acidified spots). This method is not entirely correct for restoration, but it has to be used because it is susceptible to biological erosion. Most of the adhesives used in repairs have reducible properties and are not strong enough to withstand the force of the repair machine. Reinforcement methods can use methyl plant fiber or plastic materials, which have high durability and are easy to dry, but cannot be restored. The remedy can be to dissolve methyl plant fiber in water and add 10% polyethylene glue.
Identification of damage: In order to avoid serious mistakes, it is best to inspect the book before handling it to see whether it has been repaired before and why it was damaged. If these restorations are not in original condition, the book can be removed. It is best to physically examine the book first, observe the text and graphics, count the pages, and see if there are any missing pages or maps and other related information missing. Factors such as the preservation of the seams and whether they are scattered or loose should be considered. In addition, the cover, spine, and iron protection also need to be investigated to see if the same material can be found, whether the corners of the book are damaged or brittle, and the degree of preservation and damage of the covering (decoration), etc.
In this part of the various related explorations, we also used camera photography to assist, drew sketches, made notes, and marked the number of pages that had been restored and the condition of each stack of paper.
The disassembly and restoration of books in different eras: Due to damage or age, the books have become more or less dilapidated and loose during the restoration process.
*First do the cleaning work, including cleaning dust, killing insects and removing paint. The tools used are fine brushes, general repair erasers, soap, wax, and a slightly damp rag for cleaning. Retain and record removed or cleaned adhesive materials.
*Cleaning the spine and cover requires drying, so the parts are quite fragile. The spine groove is usually the most damaged area. We use a scraper or scalpel to lift the leather. Do not damage the string. and thread. The parchment or paper fixed on the inside records their thickness and material.
*Clean the cover in the same way, starting from the spine groove or the corners or edges of the cover.
*Remove the adhesive. If the adhesive is very old, use paste to deal with it, but do not abuse it, otherwise it will stick to the books.
*If there are local cracks or biological erosion, you can use tulle or fiber paper with high-concentration methyl plant fiber or paste to affix it during binding.
*If the spine or cover is cloth, the color of the cloth should preferably be water-soluble to handle acid spots. The rest of the fabric surface can be fixed with Klucel and ethanol. It will be easier to handle when grafting or installing a new spine or cover.
*If the cover is made of paper, wet it slightly and lift it up, then use paper repair methods to deal with it.
*How to remove the back cover: If it can be removed without undue effort, first remove the back cover; otherwise, use thick methyl plant fiber or blotting paper dipped in water. tear down. Tools used to treat this part include scalpels and thermal knives. The adhesive that has been stuck to the backing page for a long time can be removed later by simply washing it. The processing also starts from the edges and spine, which are the parts that get the most damage due to frequent use. In the processing steps at this stage, you should also pay attention to removing (and restoring) the bookmarks and labels, stamps and ink pads, and fixing them and protecting them to avoid damage during water treatment.
*Removal of the inner folded edge of the cover: Whether the cover is made of leather, cloth or paper, the insert page is usually processed first so that the inner cut surface (contracanto) can be processed. Some are decorated with golden discs , but usually the storage condition is not good, but the cover should be retained so that it can be stapled back when rebinding.
*Removal of sutures: This part is handled as necessary. We first mark the pages with a pen and then erase them after repairing them. (Count the pages carefully and do not rely too much on the page number of the book itself. The number of pages in the book may sometimes be wrong, and some annotations or pictures may not be numbered). We need to know the total number of pages including lining pages. To remove stitches, you can remove them directly from the thread ends or seams (make notes if necessary). Slowly remove the stacks of paper and mark the page number and status on the removal information card to see if it is scattered or stuck. condition, whether there is a binding edge to be sewn on the book. This note card is so important that you will rely on it whenever you need to rebind it. Tools require the use of a scalpel or a sharp iron drill, and the handling must be very careful. There is a lot of glue and it is old. Especially the first and last stacks of paper have the most glue and are also the places that are most easily damaged. If the glue on the spine is too hard, you can use methyl vegetable fiber or paste to help remove it.
*Page editing: Fold each stack of paper with the help of the information card recorded when unpacking the book, and leave it untouched for at least a day to make the spine stronger and reduce the thickness.
*Re-stitching: The stitching method and materials used in the book should be done according to the records on the record card. The stitching should be strong, but should not damage the back of the stack of paper. It should be aligned in order, and the edges should be trimmed neatly at the beginning and end. (Restored books cannot use a paper cutter to cut the original edges). Use the original drilled holes to sew again (avoid drilling new rope holes). The tool for sewing is a sewing machine, which can make strong and correct sewing. It is better to do it after you have considerable understanding and practice. If the stitching is not strong, it is best to remove it and process it again.
*The string, whether of hemp, leather, or parchment material, should fit as closely as possible to the holes drilled in the original cover.
*Sewing repair: If the book is damaged and split into two halves, but the sutures are still there, make some additional stitches to connect the broken ones. If you want to enhance its durability, you can glue string to the sewing area.
Wooden boards should be repaired and joined according to the carpenter's tools, falcon head and dove glue (dove tail joint). In addition, it is necessary to understand the characteristics of the wood to avoid tightness. For some complicated cases, it is best to consult a carpenter.
*If the cover is made of cardboard and has not been disassembled, glue and paper can be used to fix the folds or damage. Damaged corners can also be redone, grafting on the edge peaks of the cover.
*If the string of the spine groove is broken, it must be joined and extended to be combined with the cover, sewn and woven again.
*Thread repair: Threads in ancient books have two functions, decorative and practical. The actual purpose is to protect the head and tail of the paper stack and strengthen the binding. In the 18th and 19th centuries, these were glued to the reinforced areas of the spine and were just toppers at the seams of the paper stacks, serving a decorative function.
The thread ends need to be saved or copied according to the original style. The common form is hemming, using thread and string to wrap two or three times around the base and then sew the next stack of paper.
*Cover repair: If the cover is damaged and cannot be repaired, base binding will be done. The clean material for the leather or cloth surface is ready and then connected to the new cover. You can use a razor or scalpel to trim the edge thickness to avoid creases during gluing. If the cover can still be repaired, use methyl plant fiber and 10% Primal to make thick viscose for small areas of damage (if it is too thin, the moisture will make the cortex black), and then use fiber paper to graft it from the back. If the leather is of poor tanning quality or scorched, you can use oil-coated paper or cloth as a base layer. After being treated with Beva and toluene, use a hot drawing knife through Remay nylon, and use it with new The covers are glued together. If it is cloth, use fiber paper as the base and then press it into a thin plate. If the newly grafted leather needs to be dyed with a color similar to the original leather, you can use ink or a commercially available leather dye, but the dyeing effect will be uneven, and the edges or the texture of the leather will easily become black or damaged. It is best to dye the entire piece of grafted cloth before grafting. If it is cloth, it is easier to handle, and the rendering effect with ink or dye is more uniform.
* Pasting of backing pages: Be especially careful when pasting repaired backing pages. It is best to use adhesive that can be restored, just in case. Finally, use a stamping machine to flatten and glue. Some cases we have dealt with so far do not require disassembly of the book. For example, if the membrane is damaged or scratched, you can use a special iron file for book repair and graft it with paper or leather.
* Corner or edge damage: This type of damage is the most common. The repair method is similar to that of the interlining film, and grafting can be used. The cardboard of the cover can be fixed with different adhesives and vise pressure. If the leather is damaged, scratched or lifted, it is best to use a pen dipped in paste to repair the damaged area using dot strokes. The best glue to make leather firm and elastic, and have good adhesion effect is paste.
Book hot stamping: Hot stamping is a part of binding work, which is quite difficult and takes a long time to complete. Hot stamping is made of pure gold wire pressed onto plates. The hot stamping of ancient books is very delicate. However, the so-called hot stamping today is not real gold, but aluminum foil. The difficulty, workload and cost are quite astonishing. The storage aspect is also different from pure gold foil stamping. Therefore, it is best for the restorer to negotiate directly with the gilder.
Parchment binding and preservation of ancient books: The so-called elastic (flexible) binding refers to books without covers. This method was discovered during the Florence flood in 1966. Seventeenth-century parchment elastic binding in the best preserved condition. The characteristics of elastic binding are: no glue is used, it is sewn with leather thread, and the edges are circled to support the cover and spine at the same time, and can also be sewn together. We can use colorless and acid-free materials. The cover can be made of parchment paper similar to the seventeenth century or modern neutral paper. It can be simply sewn. After the spine is consolidated, use some methyl plant fiber for viscose, and then add some lining. Page. If the book exceeds octavo, it usually has a cardboard cover supporting the parchment inside. The cardboard used in ancient times is usually replaced by acid-free paper. The so-called elastic binding repair also has some of the same steps: after the book is disassembled, clean it with an eraser; soak the dry and hard book cover in 50% ethanol and water, and place the parchment paper on two layers of polyethylene plastic and two layers of polyethylene plastic. Between layers of absorbent paper, use heavy objects such as wooden boards or weights to apply pressure on the outside. Repeat several times until the original shape is restored. If the leather surface is damaged, whether due to biological erosion or scorching, it can be treated with Polietinglicol 400 and manually rubbed and massaged to restore the book's moisture absorption and elasticity. The more problematic part is the text, which is usually written by hand on the spine of the book with ink. Polietinglicol has a strong dissolving power and must be handled with special care, otherwise the text will be damaged. The cardboard and lining pages are all repaired with acid-free and colorless paper. Try to use adhesive only on new areas. Adding a few drops of formaldehyde to the paste has a bactericidal effect.
Preservation measures for books: Same as paintings, control temperature and humidity, relative humidity 55% and 18 C. The library should be kept clean and well ventilated at all times. Books that have been restored are best kept in boxes. The box must be made of acid-free material, and the cloth box must be of natural color without dyeing. The best form of the box is with the top cover open and the spine facing upwards. Books that are too fragile should not be placed on the shelves, nor should they be too crowded to facilitate access to books. If the shelf is tall, arrange books horizontally and try to place books of the same size together to even out the weight.
Special equipment and materials for book repair: the necessary tools are a sewing machine to handle the sewing work; a wooden frame for the spine groove (it is best to make a sketch and order it from a carpenter), which has two spiral screws Used to make book spine grooves, and can also be used to fix books when hot stamping; Slate: used to scrape the edges of thin leather, and can also be used to press books; Manual press, disk-shaped with a side length of about 60cm. But if it is a smaller press like those used at the beginning of this century, it can be replaced by thick plywood; a punching/shearing machine is used to process the paper stack and cut the excess part of the graft.
There are two types: table type and upright type. The table type is about the size of A-3 paper. The cutting surface of the upright type is about 1m long. It is easier to use than the table type, but it is more expensive and requires a space of 1.50x2.00 meters. Due to the area, a small studio may not be able to accommodate it; on the work counter, it is best to stand while repairing, so almost all repairs rely on the work counter. The work counter must be able to support pressure, the table top must be easy to clean, and supplies such as paper and cardboard can be placed under the table. Other minor tools based on personal needs include: a scraper, which requires an oiled whetstone when using it; a paper knife, which is used to cut the size of the paper stack; scissors, which are at least large enough to cut cardboard. There are also long scissors so that they can be cut neatly with one cut; book trough pliers: a tool used to measure parallel lines when tying book spines to books; sharp iron drill (can be replaced by a scalpel): used to remove old Glue that solidifies for seams and spines; needles (used by rug weavers), both curved and straight; bristle brushes for spreading the paste evenly, synthetic bristle brushes for Processing of plastic glue; hammers (used by shoemakers), curved hammers can dig appropriate book spine grooves; wooden boards of various thicknesses (at least 16mm thick) are used to press stacks of paper or as weights to press books use.
The last point to emphasize is that the restorer needs to measure the workload and difficulty of the work. If necessary, it is best to find another professional bookbinder to cooperate with to achieve complete restoration requirements. Of course, the restorer must also understand these processing methods and process.