Get to grips with paper

All too often designers think about what's on the page rather than the page itself. Paper is an extremely important element of print design; it conveys the quality of your product and provides physical context for your design, whether you're producing a top-quality magazine or a free leaflet.

As you'll know, paper is defined by weight and paper size, according to the familiar 'A' and 'B' sizes of ISO 216. ISO paper sizes are all derived from a rectangle with the area of one square metre (A0 is 841x1,189mm). A sizes are intended to be the finished job sizes; RA sizes are to allow grip on the printing press; and SRA sizes allow for grip and bleed. B sizes are to cover oversize jobs.

In Europe, we use the familiar grammes per square metre rule (gsm) to define a paper's weight. In the metric system, the weight or substance is expressed as gsm or gm/2. It is calculated by the physical weight of one sheet of paper measuring 1x1 metre. In reality, no one actually folds a sheet of paper that large to weigh it! It is generally measured using a scaled-down measure of 10x10cm. The thickness or caliper of a sheet of paper is often described as bulk. It is measured using a micrometer and expressed in microns. Things are different in the US, where paper is measured using imperial measurement in lbs, by thickness in thousandths of an inch.

Paper used for printing is usually between 60g and 120g. A ream of copy paper is usually around the 80gsm mark, while material heavier than the 160gsm mark is considered card.

Anything between 10-35gsm is considered tissue paper. After that, up to 70gsm is lighter textweight paper, with most printer and copy paper fitting into the medium textweight of up to 100gsm. Heavy textweight paper (also light cardstock) is between 100-120gsm, while regular cardstock is up to 150gsm, with heavy cardstock after that. Most art paper used for printing brochures and magazine covers is coated with china clay (kaolin). Matte or glossy finishes are also used inside high-quality magazines. Chromo paper is similar, but is only finished on a single side - it's used for poster printing, for example. Cast-coated paper is a high-gloss paper where the coating has been allowed to harden while it's up against a polished chrome surface. The level of gloss needed is highly dependent on the purpose of the paper.

Uncoated papers come in a wide variety of finishes and quality. They are often described as offset or cartridge papers. These are typically rougher and used for more general purposes, such as for envelopes and pads. Laser papers are generally smoother and designed to work well for office printing. Uncoated text and cover papers are usually of the highest quality, with excellent reproduction for brochure use, and will generally show brilliant results when printing solids and 4-colour imagery.

Coated papers are produced by applying a coating mixture to china clay, chalk and latex. This can be done either on the paper machine (at the end of the drying process) or on a coating machine. Applying a coating has the effect of making a sheet smoother and more receptive to the ink, resulting in a technically superior printing surface. Matt-coated papers are produced by the application of the coating, which is then scraped off using a very sharp blade, leaving a smooth matt finish. Silk-finished papers are produced by slightly calendaring (polishing) the material using heat, pressure and polished rollers. High gloss papers - also known as art papers - are created by coating the paper, as with matt-coated paper, but then putting it under extreme pressure, a very high temperature and highly polished rollers.

We spoke to Leonard Foster, creative director of Flavour magazine about the paper he uses. "I chose a 300gsm cover matt laminate cover with 180gsm text. The printer offered a few options, but that was the best quality and most cost-effective for our print run. As we're an A5 magazine with 40 pages, we wanted to make the look and feel as high quality as possible, and not like the free supplements you get in the Sunday papers," he explains. This is particularly high textweight paper for a free publication, especially when you consider that Computer Arts Projects is printed on 80gsm GraphoCote paper for the inside pages. "I hope this thickness makes the readers want to keep the magazine in their collection; that they can feel the quality of the magazine," he says.

In contrast, we also spoke to Demelza Fryer-Saxby of the Yellow Pages. "Yellow Pages directories are printed on very low weight paper (34gsm) and currently contain an average of 52 per cent recycled fibre content," she explains. "The remaining virgin fibre used in the paper production process is derived from sustainably managed forests." A change in the ink used has also meant that Yellow Pages can now be recycled at certain mills, Fryer-Saxby continues. Despite its low gsm, this paper needs to be strong for printing as well as have good opacity so you can read the print; Bible paper is also around the same gsm.

As Foster suggests, decisions on paper stock should be made with your printer - they may well be able to suggest a more efficient option. Perhaps they have a deal with a particular supplier, or have another job on at the same time that is using similar paper. A bulk order could lower costs for you. Visiting your printer also has the added benefit that you can get hands-on with the paper itself.

The production of paper is highly regulated from an environmental point of view. "These days everyone needs to try and help the environment, and using paper and boards from sustainable sources is one of the ways that we are able to do that," explains Walker. Much paper produced in the UK is certified by the Forest Stewardship Council (FSC), including that used for this magazine.

Paper is a totally natural product, and is also (in theory) totally sustainable, totally biodegradable and totally recyclable. Few other manufactured products can claim this. Of course, there are environmental issues, as with any manufactured product. In the case of paper, there are a number of schemes to certify that trees used in production come from regulated forestry.

Equally, recycling plays an increasingly important part as a fibre source for paper. It's not a cure-all, however, and recycled paper should be used when appropriate; for newspapers, packaging and some graphics uses, for example. Bear in mind though that highly processed, heavily bleached bright white recycled papers may not be the best environmental choice. Finally, when it comes to disposal, encouragement of recycling initiatives is important as it can play an important part in reducing landfill, as paper is entirely biodegradable.