Paper: Know More Before You Buy

Youth and White Paper take any impression…

“A thin sheet of cellulose in the form of fibres irregularly interlaced and couched from a suspension of fibre and water.”

History: The word paper comes from the ancient Egyptian writing material called papyrus, which was woven from papyrus plants. Papyrus was produced as early as 3000 BCE in Egypt, and in ancient Greece and Rome. Paper, as we know it today, had its origins in China. Traditional Chinese records give the credit for its development to one T’sai Lun (about 105AD) who was even deified as the god of papermakers. In India, the history of handmade paper started in the year 1522 A.D when Emperor Babar came to India.
Paper Industry:The industry was once based almost entirely on softwoods such as spruce, pine, larch, fir and cedar. Paper made from this type of wood is much stronger. This paper is ideal for making products like shipping containers that require superior strength. But the finish is rougher, and that’s not as good for writing, printing and many other uses. Now Hardwood trees such as oaks and maples are also used as an ideal raw material for processing into fluting for corrugated cases as well as printing and writing papers. These trees have wood with very short fibres. Paper made from these species is weaker than that made from softwoods, but its surface is smoother, and therefore better to write and print on.The wood and paper industry is probably the only large-scale industrial system which is genuinely capable of satisfying future requirements for sustainable development. With its renewable raw material, ecologically adapted forest management techniques, environmentally-neutral processes and recyclable products, the wood and paper industry has the unique potential to become an integral part of an integrated carbon cycle based on photosynthetic conversions of water, carbon dioxide, nutrients and solar energy into a renewable woody biomass, making it one of the greatest natural cycles that control our climate and environment.

Some Important Terms:What is GSM? Abbreviation for grams per meter square; units of grammage; metric unit alternative to Basis weight.Paper density (also known as basis weight and grammage) is a term used in the pulp and paper industry and also for fabric industry to denote a measure of mass of the product per unit of area for a type of fabric, paper or paperboard. The term “density” is not used in its traditional sense of mass per unit volume. “Paper density”, rather, is a measure of the area density. Paper products that let little or no light pass through (e.g.poster board) are considered dense or heavy. Paper products that allow some light to pass through (e.g. tissue paper) are considered lightweight.A office paper has 80 g/m²(GSM),therefore a typical A4 sheet (1⁄16 m²) weighs 5 g. What is Opacity? Printers Opacity is the most commonly used term. It is the ratio of diffused reflectance and the reflectance of a single sheet of paper backed by a black body. Opacity is important in Printing Papers, Book Papers etc. What is the Difference between Brightness & Whiteness? Great confusion exists in the use of the terms Whiteness and Brightness. Brightness is the percentage reflectance of Blue Light only at a wave length of 457 mµ. Whiteness is the percentage reflectance of light at all wavelengths Brightness Whiteness Yellowness Their relevance to Paper: Brightness is the amount of reflectance of blue light at effective wave length of 457 nm. Brightness test is designed basically to measure the effectiveness of bleaching in removing yellowness. Spectral reflectance curves of same type of pulps are similar in shape. Hence a reading at a single wave length is sufficient indication of the shape of the curve. The spectral reflectance curve for an unbleached pulp starts of with a relatively low reflectance in the violet end of the spectrum and raises rapidly to a fairly high value in the extreme red end of the spectrum. Hence unbleached pulp is yellow in color. Bleaching raises the spectral reflectance curve over the whole range, but the increase is greatest in the blue violet range and less in the red range. If one were to choose an area of the spectrum in which to take measurements which would best correlate with observable changes in Brightness during the bleaching process, the blue area would be the best Since the spectral reflectance curves are different for papers of different tints, though they are made with same type of pulps, measurement at a single wave length is not sufficient to indicate the shape of the curve. Hence Brightness values do not indicate the color /whiteness of the paper. Whiteness : Whiteness is the amount of reflectance of white light at all wave lengths across the visible spectrum. Whiteness is a combination of the total reflectance of white light and the uniformity of the reflectance at all the wave lengths. A perfect white would have 100 % reflectance at all wave lengths of visible light. • Most white papers will have a total reflectance of 50-90% with variation at different wave lengths as high as 20-30%. All though the whiteness is dependent on both total reflectance and uniformity of reflectance, the uniformity is much more important than the total reflectance. Whiteness and Yellowness are very subjective quantities which are greatly dependent upon individual preference Yellowness : All papers have yellow cast, the uniformity of reflectance becomes a measure of yellowness. If reflectance measurements are made with a green filter and blue filter, the difference between the two readings is a measure of yellowness and the reading with green filter is a measure of total reflectance. From the studies of whiteness ratings made visually, it is known that yellowness is about four times as importance as the total reflectance. Hence, when four times yellowness is subtracted from the reflectance measured with green filter the result is a measure of whiteness. What is the difference between matt, silk, dull and gloss finishes? Matt coated paper generally has enough coating thickness to cover the fibre base sheet, but only minimal calendering is applied. Because the surface of matt paper is rough, light is scattered and paper gloss is low. Printed ink gloss on matt papers is better than on uncoated paper, but is still low because the ink pigments do not lie evenly, thus dispersing light in more directions and because some of the resins sink onto the sheet. With silk coated paper, the papermaker uses a combination of coating formula and calendering technique to produce a smooth, low gloss paper. Silk coated paper is smooth, with a uniform printed ink gloss and a distinctive, silky feel. Dull paper is fully coated and calendered. The differences between dull and silk paper is not always clear. In general, dull paper is rougher, glossier and has better printed ink gloss than silk. Dull paper has excellent ink holdout for sharp halftone reproduction. Gloss paper is fully coated and calendered. It is extremely smooth and has excellent ink holdout. Finally, the finish of the paper is described according to different qualities. Linen finish shows fine textured lines. A wove finish indicates an uncoated smooth surface. Stronger textured lines are used in a laid finish. Paper can be coated or uncoated, with a coating on one side or both to give it sheen. Depending upon the desired look of the finished product, the surface qualities should be compared in samples.
Paper Classification Printing papersof wide variety. Wrapping papers for the protection of goods and merchandise.This includes wax and craft papers. Writing paper suitable for stationary requirements. This includes ledger, bank, and bond paper. Blotting papers containing little or no size. Drawing papers usually with rough surfaces used by artists and designers, including cartridge paper. Handmade papers including most decorative papers, Ingres papers, Japanese paper and tissues, all characterized by lack of grain direction. Specialty papersincluding cigarette paper, toilet tissue, and other industrial papers Click here to check out our huge range of papers.	Microscopic structure of paper.
Environmental impact of paper: The production and use of paper has a number of adverse effects on the environment.Worldwide consumption of paper has risen by 400% in the past 40 years leading to increase in deforestation, with 35% of harvested trees being used for paper manufacture. Paper waste accounts for up to 40% of total waste produced in the United States each year, which adds up to 71.6 million tons of paper waste per year in the United States alone.
Conventional bleaching of wood pulp using elemental chlorine produces and releases into the environment large amounts of chlorinated organic compounds, including chlorinated dioxins.Dioxins are highly toxic, and health effects on humans include reproductive, developmental, immune and hormonal problems.Over 90% of human exposure is through food, primarily meat, dairy, fish and shellfish, as dioxins accumulate in the food chain in the fatty tissue of animals.
Future of Paper: Some manufacturers have started using a new, significantly more environmentally friendly alternative to expanded plastic packaging made out of paper, known commercially as paper-foam. The packaging has very similar mechanical properties to some expanded plastic packaging, but is biodegradable and can also be recycled with ordinary paper.With increasing environmental concerns about synthetic coatings and the higher prices of hydrocarbon based petrochemicals, there is a focus on zein (corn protein) as a coating for paper in high grease applications such as popcorn bags.