مُرَکَّب یا جوهر مایعی حاوی رنگدانه است که جهت رنگآمیزی، رسّامی، طراحی یا خطاطی بهوسیلهٔ قلم یا قلممو بهکار میرود. از انواع مرکّبهای غلیظتر برای چاپ ماشینی و دستی استفاده میشود. مرکّب، ترکیب پیچیدهای از حلّالها، رنگدانهها، رِزینها، روانکنندهها، و دیگر عناصر است. این مواد، نوع و کیفیت رنگ، روان بودنِ آن، ضخامت، و خشک شدن آن را کنترل میکنند.
مرکب یک واژه عربی است و پارسی آن اینهااست:
مرکب خوشنویسی از مهمترین ابزارهای یک خوشنویس است، و نوع سنتی آن برای کار خوشنویسی مناسب است و از انواع مرکبها، جوهرها، و محصولات صنعتی و نوین نمیشود چندان بهرهای گرفت.
رنگدانهٔ اصلیِ مرکّب خوشنویسی دوده است و مواد دیگری مانند صمغ عربی، زاج، و مازو نیز برای چسبندگی رنگدانهها و قوام یافتن مرکّب به آن میافزایند. امروزه در بازار، مرکب به دو صورت مایع و خشک عرضه میشود؛ مرکّب مایع، آمادهٔ استفاده است، اما مرکّب خشک را باید سایید، سپس آن را در آب جوشیدهٔ ولرم یا گلاب حل کرد. این محلول را باید در ظرف سربسته بهنرمی و در مدتزمان طولانی تکان داد. به این عمل «صلایه دادن» میگویند. صلایه در کیفیت مرکّب و کشش آن بسیار مؤثر است.
در گذشته به مرکب، مِداد یا مَداد نیز گفته میشد، و این نامگذاری بدانجهت بوده که قلم را مَدَد میدهد و کمک میکند تا بنویسد. همچنین، نام «مرکّب» بهایندلیل بهکار رفته که از اجزاء مختلفی فراهم آمدهاست. کلمهٔ «مَداد» به رنگهای دیگر نیز گفته میشود، ولی رنگ سیاه بیشتر بهکار کتابت میآید و به رنگهای دیگر گاهگاه احتیاج میافتد. رنگ سیاه درجاتی دارد:
۱- سیاه مطلق (پَرکلاغی یا حالک)، ۲- سیاه معمولی (قاتم)، ۳- سیاه مایل به خاکستری (سربی یا دَیجُور)، ۴- سیاه طاوسی (مایل به سبز یا مُدهام).
جهت جلوکیری از فسادِ مرکّب، باید آن را دور از آلودگیها نگه داشت و در یا سرپوش دوات را در مواردی که با آن کار نمیکنند، بست، و هرازچندگاهی (حدوداً یک ماه) مرکّبِ داخل دوات را باید عوض کرد. لیقهٔ خوب نیز از خرابی مرکّب میکاهد.
برای رقیق کردن مرکّبِ خوشنویسی آب مقطر یا آب جوشیدهٔ سردشده از آب معمولی بهتر است، و مناسبتر از آن، گلاب یا آب ریحان یا آب مازوست. (مازو برجستگیهای کرویشکلی است که تحت اثر گَزِش حشرهٔ مخصوصی برروی جوانههای درخت بلوط مازو ایجاد میشود. این برجستگیها حاوی شیرهٔ درخت مزبور است که به نام مازو موسوم است. در ترکیب مازو ۶۰–۷۰٪ تانن وجود دارد، بهعلاوه، مقدار کمی اسید کالیک و اسید آلاژیک و مقداری مواد گلوسیدی و آمیدون. در صنعت، از مازو جهت تهیهٔ مرکّب سیاه و رنگ کردن پارچهها و نیز در چرمسازی استفاده میشود).
امروزه مرکّب خوشنویسی به دو صورتِ جامد و مایع عرضه میشود. ساختِ مرکّب، روشهای گوناگونی دارد، ولی متداولترین آن، که درمیان خطاطان رایج است، بدینصورت است که ابتدا مقداری دوده (برای رنگ سیاه، و انواع رنگدانههای گیاهی برای رنگهای دیگر) را در آب جوشیدهٔ سردشده حل میکنند و داخل آن زاج سفید میریزند و سپس آن را با شعلهٔ کم میجوشانند؛ سپس آن را آرامآرام خنک میکنند. این روش، سادهترین روش ساخت مرکّب است. البته در بعضی مواقع، زعفران، پوست گردو، و برخی مواد دیگر نیز بهکار میرود.
فضائلی، حبیبالله، تعلیم خط، تهران، انتشارات سروش، ۱۳۵۶
حاجیآقاجانی، هادی، روش تدریس هنر، کتاب درسی اول راهنمایی، دفتر برنامهریزی و تألیف کتابهای درسیِ وزارت آموزش و پرورش، تهران، ۱۳۷۳
Ink is a liquid or paste that contains pigments or dyes and is used to color a surface to produce an image, text, or design. Ink is used for drawing or writing with a pen, brush, or quill. Thicker inks, in paste form, are used extensively in letterpress and lithographic printing.
Ink can be a complex medium, composed of solvents, pigments, dyes, resins, lubricants, solubilizers, surfactants, particulate matter, fluorescents, and other materials. The components of inks serve many purposes; the ink's carrier, colorants, and other additives affect the flow and thickness of the ink and its dry appearance.
Ink formulas vary, but commonly involve two components:
Inks generally fall into four classes:
Pigments are solid, opaque particles suspended in ink to provide color. Pigment molecules typically link together in crystalline structures that are 0.1–2 µm in size and comprise 5–30 percent of the ink volume. Qualities such as hue, saturation, and lightness vary depending on the source and type of pigment.
Dye-based inks are generally much stronger than pigment-based inks and can produce much more color of a given density per unit of mass. However, because dyes are dissolved in the liquid phase, they have a tendency to soak into paper, making the ink less efficient and potentially allowing the ink to bleed at the edges of an image.
To circumvent this problem, dye-based inks are made with solvents that dry rapidly or are used with quick-drying methods of printing, such as blowing hot air on the fresh print. Other methods include harder paper sizing and more specialized paper coatings. The latter is particularly suited to inks used in non-industrial settings (which must conform to tighter toxicity and emission controls), such as inkjet printer inks. Another technique involves coating the paper with a charged coating. If the dye has the opposite charge, it is attracted to and retained by this coating, while the solvent soaks into the paper. Cellulose, the wood-derived material most paper is made of, is naturally charged, and so a compound that complexes with both the dye and the paper's surface aids retention at the surface. Such a compound is commonly used in ink-jet printing inks.
An additional advantage of dye-based ink systems is that the dye molecules can interact with other ink ingredients, potentially allowing greater benefit as compared to pigmented inks from optical brighteners and color-enhancing agents designed to increase the intensity and appearance of dyes.
A more recent development in dye-based inks are dyes that react with cellulose to permanently color the paper. Such inks are not affected by water, alcohol, and other solvents. As such, their use is recommended to prevent frauds that involve removing signatures, such as check washing. This kind of ink is most commonly found in gel inks and in certain fountain pen inks.
Many ancient cultures around the world have independently discovered and formulated inks for the purposes of writing and drawing. The knowledge of the inks, their recipes and the techniques for their production comes from archaeological analysis or from written text itself.
The history of Chinese inks can be traced to the 23rd century BC, with the utilization of natural plant (plant dyes), animal, and mineral inks based on such materials as graphite that were ground with water and applied with ink brushes. Evidence for the earliest Chinese inks, similar to modern inksticks, is around 256 BC in the end of the Warring States period and produced from soot and animal glue. The best inks for drawing or painting on paper or silk are produced from the resin of the pine tree. They must be between 50 and 100 years old. The Chinese inkstick is produced with a fish glue, whereas Japanese glue (膠 "nikawa") is from cow or stag.
The process of making India ink was known in China as early as the middle of the 3rd millennium BC, during Neolithic China. India ink was first invented in China, although the source of materials to make the carbon pigment in India ink was later often traded from India, thus the term India ink was coined. The traditional Chinese method of making the ink was to grind a mixture of hide glue, carbon black, lampblack, and bone black pigment with a pestle and mortar, then pouring it into a ceramic dish where it could dry. To use the dry mixture, a wet brush would be applied until it reliquified. The manufacture of India ink was well-established by the Cao Wei Dynasty (220–265 AD). Indian documents written in Kharosthi with ink have been unearthed in Chinese Turkestan. The practice of writing with ink and a sharp pointed needle was common in early South India. Several Buddhist and Jain sutras in India were compiled in ink.
The reservoir pen, which may have been the first fountain pen, dates back to 953, when Ma'ād al-Mu'izz, the caliph of Egypt, demanded a pen that would not stain his hands or clothes, and was provided with a pen that held ink in a reservoir.
In the 15th century, a new type of ink had to be developed in Europe for the printing press by Johannes Gutenberg. According to Martyn Lyons in his book Books: A Living History, Gutenberg’s dye was indelible, oil-based, and made from the soot of lamps (lamp-black) mixed with varnish and egg white. Two types of ink were prevalent at the time: the Greek and Roman writing ink (soot, glue, and water) and the 12th century variety composed of ferrous sulfate, gall, gum, and water. Neither of these handwriting inks could adhere to printing surfaces without creating blurs. Eventually an oily, varnish-like ink made of soot, turpentine, and walnut oil was created specifically for the printing press.
In 2011 worldwide consumption of printing inks generated revenues of more than 20 billion US dollars. Demand by traditional print media is shrinking, on the other hand more and more printing inks are consumed for packagings.
Health and environmental aspects
There is a misconception that ink is non-toxic even if swallowed. Once ingested, ink can be hazardous to one's health. Certain inks, such as those used in digital printers, and even those found in a common pen can be harmful. Though ink does not easily cause death, repeated skin contact or ingestion can cause effects such as severe headaches, skin irritation, or nervous system damage. These effects can be caused by solvents, or by pigment ingredients such as p-Anisidine, which helps create some inks' color and shine.
Three main environmental issues with ink are:
Some regulatory bodies have set standards for the amount of heavy metals in ink. There is a trend toward vegetable oils rather than petroleum oils in recent years in response to a demand for better environmental sustainability performance.
Ink uses up non-renewable oils and metals, which have a negative impact on the environment.
Writing and preservation
The two most used black writing inks in history are carbon inks and iron gall inks. Both types create problems for preservationists.
Carbon inks were commonly made from lampblack or soot and a binding agent such as gum arabic or animal glue. The binding agent keeps carbon particles in suspension and adhered to paper. Carbon particles do not fade over time even when bleached or when in sunlight. One benefit is that carbon ink does not harm paper. Over time, the ink is chemically stable and therefore does not threaten the paper's strength. Despite these benefits, carbon ink is not ideal for permanence and ease of preservation. Carbon ink tends to smudge in humid environments and can be washed off surfaces. The best method of preserving a document written in carbon ink is to store it in a dry environment (Barrow 1972).
Recently, carbon inks made from carbon nanotubes have been successfully created. They are similar in composition to traditional inks in that they use a polymer to suspend the carbon nanotubes. These inks can be used in inkjet printers and produce electrically conductive patterns.
Iron gall (common ink)
Iron gall inks became prominent in the early 12th century; they were used for centuries and were widely thought to be the best type of ink. However, iron gall ink is corrosive and damages paper over time (Waters 1940). Items containing this ink can become brittle and the writing fades to brown. The original scores of Johann Sebastian Bach are threatened by the destructive properties of iron gall ink. The majority of his works are held by the German State Library, and about 25% of those are in advanced stages of decay (American Libraries 2000). The rate at which the writing fades is based on several factors, such as proportions of ink ingredients, amount deposited on the paper, and paper composition (Barrow 1972:16). Corrosion is caused by acid catalysed hydrolysis and iron(II)-catalysed oxidation of cellulose (Rouchon-Quillet 2004:389).
Treatment is a controversial subject. No treatment undoes damage already caused by acidic ink. Deterioration can only be stopped or slowed. Some[who?] think it best not to treat the item at all for fear of the consequences. Others believe that non-aqueous procedures are the best solution. Yet others think an aqueous procedure may preserve items written with iron gall ink. Aqueous treatments include distilled water at different temperatures, calcium hydroxide, calcium bicarbonate, magnesium carbonate, magnesium bicarbonate, and calcium phytate. There are many possible side effects from these treatments. There can be mechanical damage, which further weakens the paper. Paper color or ink color may change, and ink may bleed. Other consequences of aqueous treatment are a change of ink texture or formation of plaque on the surface of the ink (Reibland & de Groot 1999).
Iron gall inks require storage in a stable environment, because fluctuating relative humidity increases the rate that formic acid, acetic acid, and furan derivatives form in the material the ink was used on. Sulfuric acid acts as a catalyst to cellulose hydrolysis, and iron (II) sulfate acts as a catalyst to cellulose oxidation. These chemical reactions physically weaken the paper, causing brittleness.
Indelible means "unremovable". Some types of indelible ink have a very short shelf life because of the quickly evaporating solvents used. India, Mexico, Indonesia, Malaysia and other developing countries have used indelible ink in the form of electoral stain to prevent electoral fraud. The Indian Scientist Dr. M.L. Goel is the founding father of indelible ink in India and gave the secret formula to NPL (National Physical Laboratory) of India.
The Election Commission in India has used indelible ink for many elections. Indonesia used it in its last election in Aceh. In Mali, the ink is applied to the fingernail. Indelible ink itself is not infallible as it can be used to commit electoral fraud by marking opponent party members before they have chances to cast their votes. There are also reports of "indelible" ink washing off voters' fingers in Afghanistan.