FAQ: How should I store my Japanese prints?
Japanese prints are very susceptible to fading, so protecting them from damaging light should be a primary concern of collectors and curators. One method of storing prints out of the light is to place each print within a neutral-pH paper folder and store it stacked with others inside rigid archival solander or portfolio boxes (see image below showing a typical black "clam-shell style" storage case opened to reveal a print placed within a paper folder). The papers and the linings of the boxes must all be made of acid-free (pH neutral) materials! One advantage to this approach is ready access to prints and fairly limited storage requirements; one disadvantage is the possibility of damaging the prints during handling for viewing. Nevertheless, if prints are handled carefully, this danger falls within the "limited risk" category. One of the pleasures of viewing Japanese prints is holding them in one's hands, feeling the paper, examining the back, and so on. This should always be done with two hands, one on each side of the print, with a gentle grip, taking care not to buckle, crease, dent, or otherwise harm the print.
Do not assume that all handmade Japanese papers are pH neutral or safe for print storage. In fact, many Japanese paper folders used by collectors and dealers have been found to be slightly acidic, and a few are very acidic. It is not recommended that you store multiple loose prints together inside a single paper folder because as they move they might rub against one another, causing abrasion of the surface or a loosening of pigments not fully absorbed into the paper matrix. If the prints happen to be in environments with high relative humidity (obviously not recommended), storing them face-to-face might result in some bleeding of colors from one print to the next. If you have print designs composed of more than one separate sheet (i.e., polyptychs) or multiple sheets still connected by Japanese album backings, which you desire to keep together within a single paper folder, you should interleave with glassine sheets to avoid rubbing the front of the prints (and their pigments) against one another. Although glassine sheets are thin and more susceptible to buckling or curling than the prints, the effect over long periods of time is likely to be minimal, if any. Regular, periodic examinations of the condition of your stored prints should be sufficient to verify whether the storage conditions must be altered.
Many collectors and curators mount their prints onto rigid museum board (pH 7.0 = neutral, acid free, 100% cotton rag). Some conservators are concerned that neutral pH boards might turn acidic if exposed for long periods to environmental contaminants, and so they use a slightly alkaline board (pH = 8.0 - 8.5) buffered with calcium bicarbonate to provide extended protection, including buffering against acids formed when papers absorb sulfur dioxide from the environment. The problem specific to ukiyo-e prints is the lack of information on the pH range of the various organic and inorganic pigments. The consensus among conservators seems to be that at least some of the pigments used for ukiyo-e might have been slightly acidic, so it would probably be best to use pH neutral, non-buffered paper folders or mat boards. The thinking here is that one should at least start off with a storage environment at neutral pH, without buffering agents, so that whatever the mixture of ukiyo-e pigments (acidic, neutral, or alkaline), the print and its pigments stand a better chance of being preserved without undue interaction with the storage materials. Periodic inspection of stored prints should reveal whether the pH-neutral paper folders are interacting with the prints; if pigment/dye transfer is noted (from prints to paper folders), alternate papers (e.g., buffered) can be substituted and monitored.
Neutral pH materials that have been buffered to achieve that "neutrality" or to present a further barrier to environmental acidity will include alkaline ingredients that might interact with acidic pigments, if any, on particular ukiyo-e prints. It has not been unequivocally established whether buffered materials would be harmful or cause a change in the appearance of acidic ukiyo-e pigments (there is anecdotal evidence that in some cases they might), but non-buffered pH neutral materials would seem the best choice for storage materials. Museum boards have a high alpha-cellulose content and are free from lignin fibers or groundwood. Lignin, in particular, is a product found in cheaper, less chemically stable boards. It reacts with light and heat to create phenols and acids, which will discolor and embrittle paper. If done correctly and archivally, the mat board will offer some protection from creasing or tearing the print because it can be viewed through the window cut in the mat and does not require direct handling. However, archival mounting should be used (such as Japanese paper hinges and wheat starch paste) for safe attachment of the print to the mat board.
Some print owners have asked about storing their prints inside plastic folders or sleeves. The prints would obviously be viewable through clear plastic and thus would not have to be handled directly for viewing. Unfortunately, plastics are not acceptable materials for archival print storage. Plastics can set up a static charge that can lift off looser pigments from the paper surface, such as metallics or mica that are bound to the surface with a glue binder and are not absorbed as much into the paper as are typical pigments or dyes. In addition, some plastics are not safe materials. For example, PVC and acetates are not inert and give off chemical contaminants that can damage prints. Polyester (Mylar D) is inert, but it can have sharp edges and pose a threat of tearing the prints. Softer polypropylene sheets might cause the least problems, but, again, plastics are not considered archival storage materials. Aside from these technical considerations, the aesthetic experience of viewing prints through plastic is not a satisfactory one for many collectors. ©1999-2019 by John Fiorillo
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How do you attach a Japanese print to a mat?
If you must frame your prints (rather than store them in archival folders, as described above), the recommended method for hinging Japanese prints to mats can be summarized as follows:
- First, unless you are experienced in hinging prints to mats, you should consult a professional framer who is familiar with methods of museum-quality, archival matting and framing. All do-it-your-selfers should proceed with caution! If you lack experience in handling works of art on paper you are likely to do some harm. Using Japanese paper hinges requires the use of Wheat Starch Paste for the adhesive, which is "cooked" before use and cannot be stored for long periods for fear of bacterial growth. (You should NOT use tap water, which has contaminants harmful to paper, or a reactive vessel (i.e., made from non-inert materials) to cook the paste. Distilled water or perhaps buffered water is preferred (consult a conservator on this point.) Obviously using Japanese paper hinges is not the most convenient way to mount prints to mats, but it is the recommended archival method. Self-adhesive Filmoplast tape, although rated as pH neutral and water soluble, is not considered strictly archival because it is not always fully reversible (for example, there can be problems with "skinning" of the artwork or leaving behind some of the adhesive when it is removed). Other types of mounting tape can be quite harmful to Japanese prints and should not be used. Selecting the appropriate paper hinge requires some care. There are several types of Japanese paper hinges used in archival paper mounting that bear various Japanese names, but the names themselves are not always meaningful. It takes an experienced framer or conservator to decide on the hinge's weight and fiber quality. One goal is to select a paper hinge that will hold the artwork to the mat but will be weaker than the artwork, so that if the artwork is inadvertently pulled, the hinge will give way or tear, not the work of art.
- It also takes some practice deciding on the amount of paste needed to mount an artwork. Too much will buckle the paper from excessive moisture, too little may not hold the artwork securely.
- Commercial retail framing shops are, generally speaking, uninformed about or inexperienced with archival framing. Countless numbers of prints have been damaged (sometimes irreparably) by inappropriate framing methods. It is sad to encounter so many once-fine prints that have been compromised or ruined by gluing to mat boards or cardboard, taped around the edges to backing boards (often acidic), and trimmed (or margins folded under) to fit certain frame sizes. These faults are magnified when the prints are displayed in bright light or excessively hot or humid environments — see the next topic (How quickly do prints fade?).
Please read more about these matters and talk directly to framers experienced with archival methods. There is at least one book that offers a general introduction to the overall subject: Anne Clapp: Curatorial Care of Works of Art on Paper (New York: Nick Lyons Books, 1987). ©1999 by John Fiorillo
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How quickly do Japanese prints fade?
The fading rates of colorants in Japanese prints are not well known, but experience and preliminary scientific testing (see reference below) strongly indicate that caution is required when displaying works of art on paper. Not all pigments found on Japanese prints have been identified, and very few have been tested in a standardized manner. Various factors affect the rates of fading, among them the:
- binder used to disperse and control the colorant, such as rice starch paste
- concentration of the colorant
- the mixtures of colorants, if any
- mordants or "laking" materials used to insolubilize or precipitate soluble dyes, if any
- type of paper, including the sizing, if any, used to control absorption of the colorants
- relative humidity of the environment
- the spectral range of light radiation
- intensity of illumination
One group of researchers tested three fugitive colorants commonly used in ukiyo-e prints: aigami (Commelina communis, dayflower blue of the lily family; L. var. hortensis Makino), beni (red or pink from Carthamus tinctorius, a safflower), and ai (Polygonum tinctorium, or indigo). The rates of fading of these three colorants were compared in lightfastness with the blue-wool cloth fading standards (eight blue-dyed cloths, each designed to fade at half the rate of the preceding cloth) supplied by the International Standards Organization. Cloth no. 1 is the most fugitive, while cloth no. 8 is the most stable. The investigators found that aigami fades even faster than cloth no. 1, beni fades about as fast as cloth no. 1, and ai fades at a rate between cloth nos. 3-4.
More recent research (2005; see references #3-4 below) has found that beni is especially fugitive. It has long been thought that aigami or the organic dye produced from the hybridized dayflower was exceedingly fugitive when exposed to light. New research indicates that the colorant is only moderately sensitive to light. However, it is extremely fugitive when exposed to moisture (this would include not only direct contact with liquids but also humidity). Furthermore, the unfaded appearance of the colorant may range from warm bright blue to grayish blue depending on the length of time it has been stored in the paper carrier (the traditional form of aigami is produced as pieces of paper saturated with the colorant). To release the colorant from the paper carrier, all one needs to do is soak a piece of paper in water. When aigami is applied soon after its manufacture, it produces a warm blue; when it is used some years after manufacture, aigami produces a grayish blue. Thus the familiar grayish blue found on some 18th-century prints may at times be due not to fading or exposure to moisture, but to its initial appearance. Thus one needs to be cautious about conclusions drawn merely from the "blueness" of the aigami colorant on ukiyo-e prints, particularly when the colorant appears uniform throughout the printed area.
What does this mean in practical terms? If aigami and beni are exposed to only 5 foot-candles (corresponding to dim illumination) in a museum setting, the colors will fade noticeably after no more than 200 weeks of exhibition. This is a truly disquieting finding. Although other colorants used in Japanese prints are not so sensitive to light exposure, it remains true that pigments on Japanese prints, especially the eighteenth- and early nineteenth-century examples, are among the most light-sensitive colorants in works of art on paper. Many late-nineteenth and twentieth-century prints are also susceptible to fading.
For an example of fading on a print from the mid 1870s that was displayed in a frame for just slightly longer than a decade, see Fading of a Yoshitaki Print. For a discussion of several other examples of fading, see Fading Samples. Readers should refer to the article by Feller, Curran, and Bailie(see reference 2 below).
Collectors and curators who wish to display their Japanese prints in frames will expose the colors to fading in light. Thus they face a dilemma, whether and how long to place the prints on view. On the one hand, framing and displaying will facilitate the convenient appreciation of prints, especially for large numbers of viewers in museums or galleries; on the other hand, displaying prints for extended periods of time will fade some or many of the colorants. Please refer to Storing Prints above for the earlier FAQ "How should I store and display my prints?" for more on this issue. ©1999-2019 by John Fiorillo
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Will UV plastics protect my prints from fading?
The simplest answer is NO!
Daylight and fluorescent light often include ultraviolet radiation (UV), which is invisible to the human eye. Daylight will typically include wavelengths of radiation between 310 - 700 nm, but depending on the source, only about 3% - 7% is UV (i.e., below 400 NM). So while UV filters may help slow down the rate of fading of some colorants exposed to UV, it will do little or nothing to protect against the longer wavelengths of radiation. Certain colorants will not be protected at all with UV filtering. For example, tests of one traditional red textile dye, enji (cochineal carmine), showed virtually no difference in the rates of fading with or without UV filtering.
In addition, colorants that are especially susceptible to fading under UV radiation are also fugitive under the longer wavelengths as well, so while some protection might be gained from UV filtering, the resulting damage from the longer wavelengths could still be severe. Preliminary tests (see reference below) suggest that ai (a standard blue colorant used in ukiyo-e prints made from Polygonum tinctorium, or indigo) may fade at a rate of 1/3 that of samples without UV filtering. Yet ai is unfortunately a fugitive pigment in visible light and will still fade rather quickly.
For more about the fading of colors, see the FAQ "How fast do prints fade?" above and the examples of fading in prints by Katsukawa Shunei. Those wishing to display their prints in frames with UV plastics must therefore recognize that UV filtering will NOT block out 100% of the UV, nor will it will protect against the remainder of the visible part of the spectrum, which constitutes more than 90% of the remaining wavelengths of radiation. Conservators worry that those who frame their prints with UV filtering will develop a false sense of security, thinking that they have protected their prints against all light damage, which is not true. In addition, some colors will receive no protection at all from UV filtering.
Readers should refer to the article by Feller, Curran, and Bailie: "Identification of traditional organic colorants employed in Japanese prints and determination of their rates of fading," in: Keyes, R.: Japanese Woodblock Prints: A Catalogue of the Mary A. Ainsworth Collection. Oberlin: Allen Memorial Art Museum, 1984, pp. 253-264. ©1999 by John Fiorillo
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Can a glued print be removed from its backing?
Removing glued paper backings and the residue of the glue itself can be very difficult and sometimes impossible without damaging the print. There are a great variety of glues. Water-soluble glues are the easiest to deal with, although very thin papers are susceptible to moisture damage that could show on the front surface. Many glues cannot be treated without solvents, which in themselves can be quite harmful to Japanese prints. A conservator should be consulted to determine (1) what type of glue was used, (2) whether treatment is a viable option, and (3) if recommended, which treatment methods should be used.
While it is true that paper conservators often have the expertise and specialized equipment and materials to safely remove glued prints from their backings, there are also many cases where removal is too dangerous to attempt (some solvents are toxic!). Please do not try it yourself, as you are likely to damage the print. If you do not know of a reputable expert in paper conservation in your area, visit the website for the American Institute for Conservation of Historic and Artistic Works (AIC), which has a section on selecting art conservators who are experienced in caring for works of art on paper. ©1999-2019 by John Fiorillo
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Will restoration increase the value of my print?
Sometimes - it depends on the circumstances, and there is not always a consensus about what constitutes an improvement. In general, if the print in question is restored or repaired without any detrimental effects to what was originally part of the work of art, then the restoration should enhance both the aesthetic and commercial value. Quantifying that increase for commercial purposes would be difficult, however, and so estimating the potential increase in monetary value should be made on a case-by-case basis. Print owners should be wary of "restorations" that correct one problem while sacrificing something original to the print.
For example, "washing" a print to remove the toning (darkening or yellowing from acids in the environment or poor-quality matting) might also cause bleeding (migration or spreading) of water soluble colorants. A cleaner-looking print obtained at the expense of bleeding the colorants would offset some or all of the improvement in appearance. Such a result would be unacceptable because the print would have lost something intrinsic to its value, namely, its colors (in whatever state they were in just before restoration). A reputable professional print conservator would never intentionally wash a print when knowing that the colors would likely bleed. There are, of course, many examples of successful restorations in which creases, folds, surface dirt, toning, and stains have been removed while preserving all that was original to the print. That, in short, should be the goal in all restoration projects.
In cases where irreversible damages (such as severe creases or folds, tears, punctures, or worm holes) can only be masked cosmetically (e.g., folds partly flattened, tears mended, or holes plugged), the value of the print may not increase (though sometimes it will), but at least its original remaining attributes (colors, paper color, and so on) would remain unaffected by the cosmetic repairs, while the appearance of the print would be enhanced. Thus the work of art could be enjoyed even more than when in its damaged state. If the restoration will remove what is clearly damage (that is, what is not original), while preserving what belongs there (what is original), then the value of the print will typically increase. In ukiyo-e this is often a risky business (and expensive when done professionally). Given the fragility of ukiyo-e prints, we should always be cautious about approaching restoration projects. ©1999-2019 by John Fiorillo
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What is foxing?
"Foxing" refers to brown spots caused by one type of mold, a saprophytic fungus (living on dead organic matter). The fungus destroys the sizing in paper and discolors it. Although almost any dark spotting is frequently referred to as foxing in non-scientific condition reports on Japanese prints, some of these discolorations are actually spot staining from different molds or other sources. Technically, foxing requires that the paper has been infected by a saprophytic fungus.
Sometimes analysis under a microscope or under UV radiation is required to confirm the nature of a mold. One difference is that some molds appear "furry" when viewed by eye, whereas foxing does not. The etiology of foxing is still not clear. It may be caused by chemical reactions between iron salts in the paper and organic acids released by fungi. It is also possible that decomposition products of cellulose have settled in the areas made spongy by the activity of fungi, after which the spots have then darkened with time and dampness (see reference below).
It is helpful to note that relative humidity below 70% would be too low for the growth of fungi in paper. Thus we have a clue to preventing or at least controlling it. Conservators recommend that you (1) keep your print storage areas below 70% RH, (2) periodically inspect your prints, and (3) avoid damp, still air. Unfortunately, although a fungus can be controlled (deactivated) by correcting atmospheric conditions, it cannot be killed that way. Fungi spores tend to be very small, are pretty much everywhere, and can travel through air. They may even be present naturally as spores in almost all untreated papers. Thus fungi will lie dormant, waiting for the conditions that will promote their growth. It is recommended that all custodians of Japanese prints regularly inspect their works of art for the presence of discolorations, some of which might prove to be foxing or other molds that will continue to grow and damage the prints if left untreated. ©2000 by John Fiorillo
- Anne Clapp: Curatorial Care of Works of Art on Paper (New York: Nick Lyons Books, 1987, p. 41).
- Feller, R., Curran, Mary, Bailie, Catherine: "Idenitification of traditional Organic Colorantys Employed in Japanese Prints and Determination of their Rates of Fading," in: Keyes, Roger: Japanese Woodblock Prints: A Catalogue of the Mary A. Ainsworth Collection. Oberlin: Allen Memorial Art Museum, 1984, pp. 253-264.
- Sasaki, Shiho and Coombs, Elizabeth: "Dayflower Blue: Its Appearance and Lightfastness in Traditional Japanese Prints", in: Scientific Research on the Pictorial Arts of Asia: Proceedings of the Second Forbes Symposium at the Freer Gallery of Art (Paul Jett, John Einter, Blythe McCarthy, eds.). London: Archetype Publications, 2005, pp. 48-57.
- Sasaki, Shiho and Webber, P. "A Study of Dayflower Blue Used in Ukiyo-e Prints," in: Works of Art on Paper—Books, Documents, and Photographs: Techniques and Conservation (V. Daniels, A. Donnithorne, P. Smith, eds.).London: International Institution for Conservation of Historic and Artistic Works, 2002, pp. 185-88.
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