INTRODUCTION - SIZING
Paper sizing (āhār dādan) is a process of preparing the surface of paper to make it suitable for writing, illuminating, or painting. After a sheet of paper has been formed and dried, the cellulose fiber it contains can continue to absorb water unless it has been ‘sized,’ i.e., impregnated with a substance like starch, glue, or wax to prevent such penetration. Different techniques are available for sizing paper, depending on requirements, such as soaking or applying one or a number of layers of sizing material on the paper surface with the help of a soft brush.
In Iran, once the paper was dried, it was sized by soaking it in albumen or a starchy solution to fill in and even out the surface for painting. Before the Islamic era, in the Sassanid period (fifth–sixth century CE), the Iranians used sizing materials over the cloth to prepare the surface for writing and painting. After learning the process of papermaking from the Chinese, Iranians started the tradition of sizing paper to prepare a suitable surface for writing and painting. The chief contribution of Iranian papermakers working under Arab rule was the perfection of rag paper thanks to improved techniques for beating the fibers and preparing the surface for writing by sizing it with starch.
A number of different sizing materials are recorded in Persian historical treatises, mainly from the late Seljuk and early Ilkhanid (seventh–eighth century Hijra/twelfth–thirteenth century CE), Timurid (eighth–ninth century Hijra/fourteenth–fifteenth century CE), Safavid (tenth–twelfth century Hijra/sixteenth–eighteenth century CE), and Qajar periods (1193-1344 Hijra/1779-1925 CE) (Barkeshli 2003).
General Characteristics of Sized Papers
The study has shown that different sizing materials on paper exhibit various physical characteristics. Each sizing material has its unique properties, influencing the paper differently. Visual and physical observations revealed that starch paste, for example, imparts more body to the paper, resulting in a firmer texture. Conversely, plant mucilage, particularly from cucumber seeds, imparts a lighter body, making the paper softer compared to starch paste. Fruit and sugar syrups provide more shine to the paper's surface, making it stiffer than plant mucilage. Both vegetable and animal glue add luster to the paper, but animal glue renders it stiffer than vegetable glue. (Barkeshli, 2015)
Regarding drying, the sizing material may take some time to dry, depending on the duration of dipping and the number of layers applied. The drying process may be prolonged if the dipping or application process is repeated. (Barkeshli, 2015)
Moreover, the study demonstrated that each sizing material can react differently to biological deterioration, leading to varying levels of mould growth, including slight, moderate, and heavy growth due to Aspergillus flavus fungus. (Barkeshli & Stephan, 2023) For comprehensive publication details, please see the 'List of Publications' under the 'About' section.
The Reason Behind Sizing Paper
In a number of Persian historical treatises, it has been advised to apply sizing materials to strengthen fragile paper, reduce the fluffiness of paper fibers, and make the paper surface smooth enough for writing. In his treatises "Ādāb al-Mašq," "Rasm al-Ḵaṭṭ," and "Savād al-Ḵaṭṭ," Solṭān Aḥmad Majnun Rafiqi Heravi in mid 16th century recommends the use of soft, smooth, and even paper for writing or drawing.
Soltān Aḥmad Majnun Rafīqī Heravī in his treatise Ādāb al-Mašq (mid 16th A.D.) writes:
ای طرفه پسر که عشق داری وز عشق هوای مشق داری
رو کاغذ طرفه ای بدست آر بریان و لطیف و صاف و هموار
Oh, wondrous lad, with love so rare,
On paper fair, your words declare.
Bring forth a sheet, both pure and bright,
Crisp and smooth, a surface right
Ṣolṭān Aḥmad Majnun Rafiqi in Rasm -al Katt (940 A.H./1533 CE), writes the following:
اگر خواهی تو ای گنج معانی که وصف کاغذ نیکو بدانی
کمالش آن بود کآید پدیدار سفید و نرم و بریان، صاف و هموار
Oh, seeker of meanings, let it be known,
Paper's virtue in qualities is shown.
In its perfection, it stands rare,
White, soft, crisp, pure, a surface fair.
Ṣolṭān Aḥmad Majnun Rafiqi in Savād al-ḵaṭṭ writes:
بدان که کاغذ خوب آنست که سفید و نرم و بریان و صاف و هموار باشد...
know that fine paper is one which is white, soft, crisp, pure, and even….
The term dāru is used for sizing in Ḥaliyyat al-Ketāb (1005 A.H. /1596 A.D), while Teflisi in 12th century refers to sizing as guneh dādan. Simi mentions guneh dādan once in connection to marshmallow seed mucilage. Sizing involves three elements: a base (taḵte) for spreading paper during sizing, a sizing substance (āhār) to smooth paper fibers, and burnishing tools (mohre) to adhere sizing, making the paper even for writing.
General Techniques of Sizing Paper
Various techniques are outlined in Persian historical recipes based on the sizing materials and the desired paper type. Two general methods are recommended for sizing paper: surface application and immersion in a sizing solution. The former is typically suggested for thicker substances like rice starch, while the latter is advised for thinner substances like mucilage.
Following the description of sizing techniques in most historical recipes, guidelines are provided for drying the paper either in the shade or sunlight, either laid flat or hung on a rope, depending on the paper size. Subsequently, burnishing is recommended to smooth and polish the paper surface.
In Persian, burnishing paper is called mohreh zadan or mohreh kardan, and the tools for burnishing are known as mohreh. Various burnishing materials were employed according to the recipes, including agate stone (ʿaqiq), jade (yašm), ivory (ʿāj), glass (zejāj, abgine), crystal (bolur), and onyx (jiz’).
General Techniques of burnishing Paper
In his book, Neishāburi (593 AH/1196), provides advice on burnishing tools, emphasizing that the best stone for burnishing gold on paper or woven into textile is onyx (jiz’). The recipe reads as follows:
و خاصیت مهین او آن است که زرهایی که بر کاغذ نهاده باشند بدان مهره زنند تا برّاق شود. و همجنین زر حلّ کرده را چون بدان چیزی نوشته باشند تا بدان مهره نزنند براق نشود. و جامه های زر کشیده هم بدان مهره زنند تا روشن و هموار شود، و این خاصیت مختص است به جزع و هیچ سنگ را این خاصیت نیست
Its most remarkable property lies in its ability to burnish the gold laid on paper, giving it a glossy appearance. Additionally, if one writes with dissolved gold, it will not achieve a glossy finish unless burnished with onyx stone. To achieve smoothness and shine, garments woven with gold thread are burnished, and this unique property is specific to onyx, as no other stone possesses this quality.
Sometimes, even a person's bare hands were used to smooth the surface of paper. A hard and smooth base made of flint (čaqmāq) was also employed, and a wooden board served as the base for burnishing and sizing paper. For example, Bābā Shāh-e Isfahanī, in Adāb al-Mašq (16th century), after advising to dye paper with henna, saffron, and a drop of ink, mentions sizing the paper with starch. He provides a recipe for the burnishing process, which reads as follows:
و باید که ساز آهار از نشاسته کنند و در وقت آهار کردن آن قدر دست بمالند که در جسم کاغذ نفوذ کند، و در وقت مهره کردن کاغذ را نم کنند تا از گرمی مهره نسوزد. و خوبی مهره آن است که چنان روشن شود که عکس روی در وی نماید
Starch should be made for sizing, and during the sizing process, the paper should be rubbed until it thoroughly penetrates the paper's body. When burnishing, the paper needs to be moistened to prevent it from burning due to the heat generated by the burnisher (mohreh). The excellence of burnishing lies in making the paper so shiny that one's reflection can be seen on its surface.
To strengthen fragile paper, minimize the fluffiness of paper fibers, and create a smooth surface suitable for writing, Mohammad Bokhari outlines the paper sizing techniques in detail in his work "Favāyed al-Ḵoṭuṭ" (995 A.H./1587 A.D.) as follows:
و دیگر طریق مهره کشیدن آن است که اوّلاً تختۀ مُهره پاکیزه می باید و شیشۀ او پاکیزه و بی گره و بی رگ می باید. و مهره را اعتدال باید کشید نه سخت و نه سست. و باید که رَخی و خطّی در کاغذ نباشد و اگر باشد نماند. و از هر طرفی که مهره کشیدی با آن طرفِ دیگر را بر بالای او باید کشیدن تا هموار و به یک منوال آید.
The technique for burnishing involves using a clean wooden board and a clean glass for the process, ensuring it is smooth without any irregularities. The burnishing tool should be applied with moderation, neither too strong nor too weak, leaving no traces or lines on the paper. It's crucial that there are no bumps or creases on the burnishing tool. The burnishing process should be carried out on both sides to achieve a smooth and uniform result.
مهرهٔ کاغذ آنچنان باید که رخ رخ بر او نه بنماید
The burnishing tool should gently graze,
Leaving the paper smooth, no lines to raise.
و دیگر بعد از این که مُهره کشیدی، باید که آن کاغذ را در تهِ تختۀ سنگی مانی چندان روز که گذشت بعد از آن گرفته به او کتابت کنی که بسیار خوش می شود. و اگر خواهی که الحال به همان کاغذِ تازه مُهره نویسی، باید که در آن کاغذ دم اندازی. همچنین که به حکم کاغذ مذکور می گردد و نیز خوشْ قلم می شود.
After burnishing, it is essential to let the paper rest beneath a flat stone for several days before commencing writing. This process enhances the quality of the writing surface. Alternatively, if immediate use is desired, the paper should be allowed to air. This practice not only prepares the paper promptly for writing but also ensures the excellence of the calligraphy.
An anonymous author in his treatises, Resāleh dar Bayān-e Ḵaṭṭ va Morakkab va Kāḡaḏ va Sāḵtan-e Ranghā (19th century) has given the same tips for burnishing process as mentioned above in poetry form. The recipe reads as follows:
مهرهٔ کاغذ آنچنان باید که رخ رخ بر او نه بنماید
تختهٔ مهره پاک باید شست زورِ بازو ولی نه سخت و نه سست
The burnishing process should be so,
That it reveals no flaws upon the paper's glow.
The burnishing board must be pristine and neat,
Strong arms, but not too hard, nor weak.
Historically, in addition to the type of fiber it contained and its place of production, paper was identified by various names, often based on the sizing of the sheets. For instance, in Resāle-ye ḵošnevisi (1120 A.H./1708 A.D.), there are remarks about ḵaṭṭaiʾi paper: 'To size ḵaṭṭaiʾi paper, whether for exercise or calligraphy, if the starch is thick, the process is repeated two or three times. Simi (837 AH/1433 A.D.) also list the name of papers that are well-sized and that is better than other papers, The recipe reads as follows:
کاغذ های جمیع بلاد را تجربه کرده اند، آنچه پسندیده تر ازهمه اینست کاغذ سلطانی، بغدادی و وزيری و دمشقی و مختاری آملی و حریری و بنگالهٔ و اشخواری سمرقند که بر آن اعتماد است و کاغذهای جایهای دیگر اکثر شکننده و نشو کننده و ناپایدار است
Various papers from different regions have been tested, and among them, the most esteemed and reliable are Soltāni, Baghdādi, Vaziri, Dameshqi, Mokhtari Amoli, Hariri, Bangāleh, Ashkhari, and Samarghandi papers. Papers from other places are often brittle, porous, and unstable.
In Ḥaliyyat al-Ketāb of Majmu‘at al-Sanāʿi (1005 A.H. /1596 A.D), there is a recipe for creating paper similar to Baghdadi paper, a well-known type produced in Baghdad and referenced in numerous Persian historical treatises. After detailing the technique for making sizing paper using rice, the recipe concludes:
و کسی از بغدادی فرق نتوان کرد....…..
….. and nobody will be able to distinguish this paper from Baghdadi paper…
TRADITIONAL VEGETABLE BASE SIZES
The first category consists of plant-based sizes, primarily polysaccharides formed by the union of numerous sugar molecules. This group includes polysaccharide starches, gums, mucilage, fruit extracts, and rock sugar. Sizing materials in this category are hygroscopic, soluble in water, and generally insoluble in organic solvents.
