{"id":6768,"date":"2026-08-31T13:00:25","date_gmt":"2026-08-31T13:00:25","guid":{"rendered":"https:\/\/cartapro.pl\/?p=6768"},"modified":"2026-08-27T13:02:52","modified_gmt":"2026-08-27T13:02:52","slug":"paper-strengthening-using-japanese-tissue-conservation-lamination-technique","status":"publish","type":"post","link":"https:\/\/cartapro.pl\/en\/wzmacnianie-papieru-bibula-japonska-technika-laminowania-konserwatorskiego\/","title":{"rendered":"Strengthening paper with Japanese tissue: conservation lamination technique"},"content":{"rendered":"<p class=\"wp-block-paragraph\"><strong>Reinforcing paper with Japanese tissue is one of the oldest and most valued conservation techniques used in saving documents, books and prints. It involves lining weakened paper with thin washi tissue, allowing it to regain mechanical integrity without interfering with the original. The method is used for archival documents, book leaves, prints and binding elements.<\/strong><\/p>\n\n\n\n<h2 class=\"wp-block-heading\">What does strengthening paper with Japanese tissue involve, and when is this method used?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The method consists of manually lining or doubling weakened paper with thin Japanese tissue (washi) using reversible conservation adhesives. In specialist literature, this procedure is referred to as lining or doubling, rather than classical lamination.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The technique is applied both unilaterally and bilaterally. Unilateral reinforcement is sufficient for surface tears and cracks. Bilateral <strong>re-gluing<\/strong> it is used for very fragile paper that, without support from both sides, would not withstand further use or digitisation.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Tissue papers and Japanese papers \u2013 how to choose the right material for the type of damage?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Tissue papers and Japanese papers available on the conservation market vary in weight, fibre composition, degree of bleaching and texture. Selecting the material for a specific task requires the consideration of several parameters simultaneously.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">How to choose the weight of Japanese tissue paper?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Grammage is one of the most important criteria for selecting tissue paper. Tissue paper with a grammage of 2\u20139 g\/m\u00b2 is used for delicate graphics and archival documents, 10\u201320 g\/m\u00b2 for book leaves, while varieties above 20 g\/m\u00b2 are used for filling losses and reinforcing spines and corners.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Kozo, gampi or mitsumata \u2013 how do the fibres differ?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The fibre composition affects elasticity and ageing resistance. Kozo paper is the most common and is available in a wide range of grammages. Mitsumata provides a smoother and more silky surface. This can be useful for documents with delicate print or drawings. Gampi is characterised by a natural sheen, a very smooth surface and high resistance to insects. The more difficult application of adhesives is due to its natural sizing, which limits the wetting of the paper by water-based binders.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Colour and texture of tissue paper \u2013 what to look out for?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The colour of the tissue paper should be close to the tone of the original. For historical documents, a shade matching aged paper is most commonly chosen so that the reinforcement is as inconspicuous as possible.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Surface texture matters for documents with a delicate paint or graphic layer. Smooth tissue paper does not interfere with the readability of text or graphic details once applied. Tissue paper with a distinct texture can be visible against the light. In some cases, this is undesirable.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">How to prepare a document or book for paper strengthening with Japanese tissue?<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">How to strengthen documents written with iron-gall ink?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The first step is to assess the condition of the building. The conservator checks:&nbsp;<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>degree of paper brittleness,\u00a0<\/li>\n\n\n\n<li>presence of impurities,\u00a0<\/li>\n\n\n\n<li>biological activity and\u00a0<\/li>\n\n\n\n<li>stability of the writing or printing layer.\u00a0<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">If the document contains water-sensitive inks or colourants, an assessment of their stability must be carried out prior to treatment.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Special care is required for iron-gall inks, contact of which with water can cause the migration of iron ions and accelerate the degradation of paper.<\/strong> In such cases, appropriate diagnostics are used and \u2013 depending on the results \u2013 anhydrous solutions, e.g. Klucel G in alcohol.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">How to prepare a document before laminating?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The second step is cleaning the surface. Loose dust is removed with a soft brush or a conservation eraser. Surface grime requires assessing whether it can be removed dry or if washing is necessary. Washing is carried out before lining. Never after.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The third step is the preparation of the work area. A clean, flat surface is needed \u2013 preferably glass or stainless steel \u2013 and sheets of tissue paper cut or torn with an excess of a few millimetres beyond the edge of the reinforced area. Tearing the tissue paper instead of cutting it with scissors produces a frayed edge. Once dry, this is less noticeable than a sharp cutting line.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The fourth step is the preparation of the adhesive. Methylcellulose, starch paste (rice or wheat) and Klucel G are most commonly used. Methylcellulose allows more time for adjustment, starch paste provides a stronger bond, whereas Klucel G is used for water-sensitive objects.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Paste should ideally be prepared immediately before use and stored for a maximum of 1\u20133 days under refrigeration. Methylcellulose remains stable for many weeks or months, and Klucel G solutions prepared in alcohol for even 9\u201312 months. The adhesive concentration should be chosen to suit the weight of the tissue paper and the condition of the object, and a test on similar paper should be carried out before starting work.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Step-by-step paper strengthening with Japanese tissue \u2013 application, backing and drying<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">How to apply Japanese tissue paper correctly?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Glue is applied in a thin, even layer to the tissue paper, not to the original. Once saturated, it becomes flexible and easily adapts to the surface of the document. The tissue paper is then transferred to the original, positioned without shifting and smoothed from the centre towards the edges, removing air bubbles. When reinforcing tears, it should overlap both sides of the damage by 5\u201310 mm, and when filling losses, it is cut with a slight excess.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">How to properly dry a reinforced document?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Drying is carried out under a light load or between sheets of dry blotting paper and boards. The object should not dry freely, because moisture from the glue causes the paper to wrinkle. Drying time depends on the thickness of the glue and ambient conditions - usually ranging from a few hours to a full 24 hours.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Once dry, check whether the blotting paper adheres evenly and whether the edges are not lifting. In professional conservation studios, polyester non-woven interleavings, blotting papers and vacuum suction tables are also used to limit paper deformation during drying.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">If the reinforcement is to be invisible, once dry, the protruding edges of the tissue can be gently wiped away with a damp brush. This causes them to blur and blend into the surface of the original.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">The most common mistakes when reinforcing paper with Japanese tissue<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The most common mistakes when strengthening paper with Japanese tissue are rarely spectacular. More often, they are subtle and only reveal themselves over time.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">The most common mistakes when backing paper<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Too high a concentration of adhesive is one of the most common problems. Thick adhesive bleeds through the tissue paper and penetrates the structure of the original. This makes subsequent removal of the reinforcement difficult or impossible. The principle of reversibility is paramount in conservation: every treatment should be reversible without damaging the object.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Applying glue directly to the original instead of the tissue paper leads to uneven saturation and difficulty in controlling the amount of glue. The original, saturated with glue, loses its rigidity and can deform before the tissue paper is applied.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Drying without weight causes wrinkling. Paper shrinks unevenly as it dries, and without pressure it deforms permanently. The load should be even and not too heavy \u2013 a few kilograms distributed on a flat board is enough.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Choosing tissue paper with too high a substance for a delicate document changes its mechanical and optical properties. The reinforcement should be as minimally invasive as possible \u2013 both visually and structurally.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">How to avoid damaging the original?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Skipping the glue test on a sample is a risk not worth taking. Before starting work on the original, always check how the adhesive behaves on a scrap of similar paper and whether it causes the ink or paint to bleed.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Effects of paper strengthening with Japanese tissue \u2013 durability, aesthetics and conservation safety<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Correctly executed paper strengthening with Japanese tissue yields durable and aesthetically neutral results. The document regains its mechanical integrity and can be safely stored, digitised and made accessible.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">What does the durability of the reinforcement depend on?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The durability of the reinforcement depends on the quality of the materials used and the storage conditions. Japanese tissue papers made from natural, acid-free fibres have a very long lifespan \u2013 comparable to the best archival papers. Methylcellulose- and starch-based adhesives are chemically stable and do not yellow with age. This distinguishes them from synthetic adhesives used in industrial lamination.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Traditional washi does not always meet the formal requirements of the ISO 9706 standard regarding alkaline reserve, but thanks to its high alpha-cellulose content and very low lignin content, it is exceptionally durable.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Will Japanese tissue paper be visible?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The post-treatment aesthetics depend on the choice of tissue paper and the precision of the work. Thin tissue paper applied to a document with printed text is practically invisible to the naked eye. Held up to the light, the delicate fibre structure is visible, but this does not interfere with reading the content. For documents with drawings or watercolours, the choice of tissue shade is more important, because even neutral white can alter the perception of the original's colours.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Conservation safety means that the treatment does not accelerate the degradation of the object and does not preclude future interventions. Japanese tissue and conservation adhesives meet this condition if applied in accordance with professional standards. Low-quality materials, acidic adhesives or papers containing fillers may damage the original over time. Therefore, the selection of materials from proven suppliers has a direct impact on the safety of the entire treatment.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">How to choose materials that comply with archival standards?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>In archival applications, it is worth choosing materials that meet the requirements of standards regarding the permanence of paper and materials for collection storage (including ISO 9706 and ISO 16245), especially when the conserved object is to be stored long-term.<\/strong><\/p>\n\n\n\n<h2 class=\"wp-block-heading\">What materials and accessories are needed for professional paper strengthening?<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">Basic conservation materials<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Tissue papers and Japanese papers in various weights are essential. It is worth having at least three weights in the studio:&nbsp;<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>the thinnest one for delicate documents,\u00a0<\/li>\n\n\n\n<li>average for library cards and\u00a0<\/li>\n\n\n\n<li>thicker one for filling gaps.\u00a0<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Tissue papers are stored in a dry place, away from sunlight, preferably in rolls or between sheets of acid-free paper.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Conservation adhesives \u2013 methylcellulose, rice or wheat starch paste, Klucel G \u2013 are chosen according to the type of object and working conditions. Each adhesive requires a different method of preparation and has different working properties. It is worth knowing their characteristics before starting work.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Tools needed for paper strengthening<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Basic tools include soft brushes for applying glue and smoothing tissue paper, work pads made of glass or stainless steel, silicone or Teflon film, weighted drying boards, as well as a scalpel, scissors, a ruler, a soft pencil, and a pipette for dispensing glue. Professional conservation studios also use magnifying glasses or stereomicroscopes.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The quality of the materials has a direct impact on the outcome of the treatment and the safety of the object. Japanese tissues and papers intended for conservation should be free of acids, lignin and fillers, and their parameters should be confirmed by the manufacturer or supplier. This is not an area where it is worth cutting costs at the expense of the durability and safety of collections.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Strengthening paper with Japanese tissue \u2013 FAQ<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>What is paper strengthening with Japanese tissue?<\/strong><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">This is a conservation technique involving the lining of weakened paper with thin Japanese tissue (washi), which reinforces the document without permanently altering the original.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>When is Japanese tissue used for paper strengthening?<\/strong><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">The method is used for repairing archival documents, book leaves, prints and binding elements, especially when the paper is brittle or damaged.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Is reinforcement with Japanese tissue paper reversible?<\/strong><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Yes. A properly executed reinforcement can be removed in the future without damaging the original paper.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>How to choose the right weight of Japanese tissue?<\/strong><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">The paper weight is chosen according to the type of object and the damage \u2013 the thinnest tissues are used for delicate documents, while thicker ones are used for filling losses and reinforcing spines.<\/p>","protected":false},"excerpt":{"rendered":"<p>Wzmacnianie papieru bibu\u0142\u0105 japo\u0144sk\u0105 to jedna z najstarszych i najbardziej cenionych technik konserwatorskich stosowanych przy ratowaniu dokument\u00f3w, ksi\u0105g i grafik. Polega na podklejaniu os\u0142abionego papieru cienk\u0105 bibu\u0142\u0105 washi, dzi\u0119ki czemu odzyskuje on sp\u00f3jno\u015b\u0107 mechaniczn\u0105 bez ingerencji w orygina\u0142. Metod\u0119 stosuje si\u0119 do dokument\u00f3w archiwalnych, kart ksi\u0105\u017ckowych, grafik oraz element\u00f3w opraw. Na czym polega wzmacnianie papieru [&hellip;]<\/p>\n","protected":false},"author":3,"featured_media":6769,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_breakdance_hide_in_design_set":false,"_breakdance_tags":"","footnotes":""},"categories":[1],"tags":[],"class_list":["post-6768","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news"],"_links":{"self":[{"href":"https:\/\/cartapro.pl\/en\/wp-json\/wp\/v2\/posts\/6768","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/cartapro.pl\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/cartapro.pl\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/cartapro.pl\/en\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/cartapro.pl\/en\/wp-json\/wp\/v2\/comments?post=6768"}],"version-history":[{"count":1,"href":"https:\/\/cartapro.pl\/en\/wp-json\/wp\/v2\/posts\/6768\/revisions"}],"predecessor-version":[{"id":6770,"href":"https:\/\/cartapro.pl\/en\/wp-json\/wp\/v2\/posts\/6768\/revisions\/6770"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cartapro.pl\/en\/wp-json\/wp\/v2\/media\/6769"}],"wp:attachment":[{"href":"https:\/\/cartapro.pl\/en\/wp-json\/wp\/v2\/media?parent=6768"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cartapro.pl\/en\/wp-json\/wp\/v2\/categories?post=6768"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cartapro.pl\/en\/wp-json\/wp\/v2\/tags?post=6768"}],"curies":[{"name":"well played","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}