How Your Magazine is Made: Paper and Ink

Aniqah Majid goes back to basics to learn how the paper and ink used for TCE is produced

WITH 20,000 copies printed every month, it takes a lot of paper and ink to bring TCE together. For each print run, the magazine needs almost 5 t of paper and more than 100 kg of ink - made up of black, yellow, magenta, and cyan.

The paper

TCE uses two types of paper: the paper for the cover and the paper for the inner section (basically everything contained within). Both paper types have a silk coating which gives them a blunt sheen, with the cover being smoother and thicker.

This comes down to the pulp. Pulp can be made mechanically, chemically, and from recycled paper, with paper mills typically using a combination of all three.

The TCE inner section paper, called Ultra Silk, is made by European paper manufacturer UPM Communication Papers at its Caledonian paper mill in Scotland.

The mill is the only producer of lightweight coated magazine paper in the UK, and sources the bulk of its wood, namely Sitka spruce, from Scotland.

The Caledonian mill uses a mixture of mechanical and chemical pulp to make the base paper, before a coating is applied to both sides of the paper.

Andrew Johnston, UPM’s development manager who has worked at the mill since it began operation in 1989, said: “[The Ultra Silk paper] contains about 50% mechanical pulp and 15% chemical pulp, and then the other 35% is coating. On average, around two-thirds of paper is fibre and a third is coating.”

Johnston explained how newspapers are often made wholly from mechanical pulp because the material is less expensive to produce. Chemical pulp is used widely for magazine paper as it is stronger, a key requirement for the coating process.

Unlike mechanical pulp, where UPM uses ceramic or diamond-surfaced grinders to turn 1.5 m logs into pulp, chemical pulp is made from wood fibres which are separated in an alkaline chemical solution.

Johnston added: “The fibres from chemical pulp are not as damaged as the fibres we produce from mechanical pulp, so chemical produces a much stronger pulp.”

The Caledonian mill only produces mechanical pulp, sourcing its chemical pulp from European suppliers.

Mechanical pulp then goes through a process of bleaching, with hydrogen peroxide used to brighten the pulp. It is then stored and ready to go through the paper machine.

The Caledonian mill’s paper machine stretches to a length of 101.4 m and width of 8.5 m and runs at a speed of 45mph.

Converting dilute pulp into finished sheets of paper in 7.5 seconds, the machine goes through five stages of production.

First, the different types of pulp are blended and laid on a fabric bed made from polyester and polyamide wires which gently remove water from the pulp.

Through the pressing and drying stages, the paper is dewatered even further, the latter being the most energy intensive, as 35 steam cylinders and six vacuum rolls are used to dry out the sheets.

A thermal roller is used to control the thickness (caliper) and smoothness of the finished paper sheet – the caliper of a finished sheet can range from 50–70 micrometres (µm). At the end of the paper machine the paper sheet is wound onto an 8 m wide roll with one jumbo roll consisting of 85,000 m of paper and weighing around 30 t.

The final stage of paper production involves coating, and comes in matte, silk, and gloss. For TCE’s inner section, the sheets are given a silk finish. The coatings are made from a combination of organic and synthetic chemicals, including calcium carbonate for brightness, China clay for gloss, and latex for strength.

The cover paper, called Magno Satin, is developed by South African paper manufacturer Sappi at its European production facility, Gratkorn Mill in Austria. The mill, which has been in operation for more than 400 years, relies primarily on spruce wood and increasingly on recycled wood chips from sawmills to make its pulp.

The pulp-making process at the Austrian mill differs from UPM’s Caledonian mill, as Gratkorn produces chemical, chlorine-free magnefite pulp. Wood chips are fed into a digester, of which Gratkorn has seven, and cooked down in an acid solution to dissolve the wood lignin and plant fibres, making pulp.

The mixture then follows a similar process to the Caledonian mill of bleaching, drying, and coating, before being spooled into reels.

The defining difference between the papers come from their thickness, with the inner section paper being 65 gsm, and the cover being more than twice as thick at 150 gsm.

Inks

TCE is printed using the lithographic process, where an image is etched on to an aluminium plate with marked hydrophilic and oleophilic areas, where the ink can and cannot go.

Adam Walker, the operations director at TCE’s printers, Precision Colour Printing (PCP), said: “The lithographic process relies on the chemical principle that ink and water are immiscible, meaning they do not mix.”

Walker explains how lithography involves two printing methods, web offset printing and sheetfed printing, the former commonly used for newspaper and high-volume magazine and catalogue printing. Sheetfed is used for the cover of TCE, while web offset is used for the internal pages.

For the cover pages, PCP uses an ink sourced from European printing company Flint Group called Flint PremEco 2200, and for the internal pages, it sources an ink from TOYO INK, owned by Japanese chemical manufacturer Artience, called Toyo Steraspeed.

Sheetfed inks are part of a family of offset inks, including heat-set and cold-set, which are typically oil-based to withstand their dilution and reaction to water.

Offset inks are made to retain colour on various substrates of paper and dry in short time. These inks are made of colour pigment, a solvent oil that holds the pigment particles together, and additives that determine the drying, smell, and resistance of the ink.

Though inks were likely originally made from animal fat, petroleum-based solutions in the form of mineral oils began to be introduced in the early 20th century due to their quick-drying properties. Around 50–70% of lithographic printing ink is made up of some type of oil, but increasingly that is not always mineral oil.  

To more sustainable times

The process of manufacturing paper and ink relies heavily on energy in the breakdown and drying of pulp, and fossil fuels in the making of inks.

However, ink manufacturers are targeting energy and resource efficiencies to improve their carbon footprint, moving away from fossil fuel-based solvents to ones made from vegetable and soybean oil.

Last year, Flint removed mineral oil from its sheetfed process inks after the European Printing Ink Association (EuPIA), of which it is a member, found that oil contained carcinogens – the French government prohibits the use of mineral oil in commercial and packaging ink to 1%, which will reduce to 0.1% in 2025.

Roy van der Pijl, Flint Group’s commercial director of offset packaging solutions, said: “Although most of our sheetfed ink ranges were already made from sustainable, bio-renewable raw materials, we recognised that using mineral oil in the remaining few was hindering our sustainability efforts.

“That’s why we’ve conducted this review and why I am delighted to announce that our remaining mineral oil-based sheetfed process inks are now being produced from more sustainable raw materials.”

Artience is also a member of EuPIA and has said that all its inks and varnishes are made from non-mutagenic, non-carcinogenic, and non-reprotoxic raw materials.

Paper sustainability comes in the form of domestic wood sources and efficient use of energy, with Johnston pointing to the efficiency gains made at UPM.

He said: “The paper manufacturing process uses a lot of electricity, as well as steam to evaporate water from the process. When we started up, we had a boiler that burned a mixture of coal and bark from the pulp wood supply, as fuel.

“In 2009, we invested in a biomass combined heat and power plant. Sourcing locally in Scotland, we stopped burning coal and used biomass to fuel the boiler.”

The Caledonian Mill also uses a high pressure 25 MW turbine that supplies 60% of the mill’s electrical need, with the remaining 40% coming from the National Grid via a local substation.

Like heavy industry, the pulp and paper sector has committed to climate neutrality by 2050.

On page two of TCE, you will find a certified label from the Forest Stewardship Council (FSC), the international organisation responsible for the world’s forests. This lets you know the paper this magazine is printed on is sustainably sourced.

To the left of that label, you will see another telling you to recycle the magazine once you are done reading it, putting it back into the pulp supply chain and on the path to a new life as anything from a newspaper to a cardboard box.