All about paper

There is a lot to know about paper. Some of the important things to consider when you are producing for print include paper formats, paper types and when to use  a particular one, surface finishing and binding process.

Paper formats:

While there are many paper formats, one that is commonly used is ISO (International Organization for Standardization)/DIN (German Institute for Standardization) series. The A (preferred sizes) and B series accepted by most of the countries. However, US and Canada have slightly different variations on those standards.  When people in the US and Canada reach for a sheet of paper to write or print on, chances are they reach for a piece of Letter-sized paper (also known as US Letter), measuring 8.5˝ by 11˝. With few exceptions, when people everywhere else reach for a sheet of paper to write or print on, they reach for a piece of A4-sized paper, measuring 210mm by 297mm.

The reference standard (AO) for ISO series is a square meter. The shorter side of the sheet is in ratio of 1 to root 2 (1.414). Each format is twice or or half as much as the next format in the series. The ISO/DIN series are sized in millimeters, not inches.

Visual representation of ISO/DIN paper sizes.

American Paper Sizes:

Name Width Depth Comments
Letter 8.5″ 11″ Also in double, half or quarter size
Legal 8.5″ 14″
Ledger 11″ 17″ Also called tabloid (see British newspapers)
Broadsheet 17″ 22″ As used in newsprint (see British newspapers)
Old (untrimmed) paper size 12″ 9″
“Dollar bill” 7″ 3″ Used for origami – larger than a modern dollar bill

ISO Paper/Trim Sizes:

Name MM Inches Name MM Inches
ISO A Series ISO B Series
4A 1682 x 2378 66 1/4 x 93 5/8 4B 2000 x 2828 78 3/4 x 111 5/16
2A 1189 x 1682 46 13/16 x 66 1/4 2B 1414 x 2000 55 11/16 x 78 3/4
A0 841 x 1189 33 1/8 x 46 13/16 B0 1000 x 1414 39 3/8 x 55 11/16
A1 594 x 841 23 3/8 x 33 1/8 B1 707 x 1000 27 13/16 x 39 3/8
A2 420 x 594 16 1/2 x 23 3/8 B2 500 x 707 19 11/16 x 27 13/16
A3 297 x 420 11 11/16 x 16 1/2 B3 353 x 500 13 7/8 x 19 11/16
A4 210 x 297 8 1/4 x 11 11/16 B4 250 x 353 9 13/16 x 13 7/8
A5 148 x 210 5 13/16 x 8 1/4 B5* 176 x 250 6 15/16 x 9 13/16
A6 105 x 148 4 1/8 x 5 13/16 B6 125 x 176 4 15/16 x 6 15/16
A7 74 x 105 2 15/16 x 4 1/8 B7 88 x 125 3 7/16 x 4 15/16
A8 52 x 74 2 1/16 x 2 15/16 B8 62 x 88 2 7/16 x 3 7/16
A9 37 x 52 1 7/16 x 2 1/16 B9 44 x 62 1 3/4 x 2 7/16
A10 26 x 37 1 x 1 7/16 B10 31 x 44 1 1/4 x 1 3/4

There are also untrimmed or oversized paper formats. These are larger, as they are not trimmed to an A series format until after printing, folding and binding.

RA Series Formats
RA0 860 × 1220
RA1 610 × 860
RA2 430 × 610
RA3 305 × 430
RA4 215 × 305

Paper Weight and Types:

The weight of paper is measured per unit of area in grams per square inch. The commonest paper and card weights:

74 20lb bond/50lb text Most often found in your everyday copy machine.
90 24lb bond/60lb text Generally multipurpose paper used in the office printer. Also the most popular business letterhead or stationary weight.
105 28lb bond/70lb text Perfect weight for brochures and presentations. Excellent for 2-sided printing with minimal show through.
120 32lb bond/80lb text Perfect weight for brochures and presentations. Excellent for 2-sided printing with minimal show through, while being slightly heavier than the 28lb.
145 67lb bond/50lb text Often considered the lightest of the cardstocks, great for self mailers with a flexible “soft feel” quick drying surface.
165 90lb index A durable cardstock with a smooth, hard surface for medium applications.
175 65lb cover A sturdy stock with a superb “soft feel” fast drying surface. Great for postcards, menus and posters.
200 110lb index Both 90 and 110lb index are the common weights for tabs, dividers and manila folders. The average weight of an index card for heavier applications.
215 80lb cover A heavy cardstock, your most conventional business card weight. Available in a wide variety of textures and finishes. This sheet is printed on 80lb cover.
255 140lb index For super heavy weight applications.
260 100lb cover A noticeably heavier cardstock often used for flat cards or invitations.

In addition to paper weight you have also to consider paper thickness (which sometimes gets mistaken for paper weight). Paper of the same weight can have different thickness. The relationship between paper thickness and paper weight is defines as paper volume: one and one-and-a-half; two and two-and-a-half. Glossy illustrated paper usually has 0.75-0.8 volume; matt coated illustrated paper – 0.75-1.0; anything from 1.0 and up is considered to be voluminous paper types.

Paper types characterized in a various ways. There are so many types that possible criteria used can be characterized by manufacturer, composition, weight, surface quality and they purpose for which they it’s used.

Coated and Uncoated paper:

Coated papers are the type that have been coated with a substance containing a pigment on one or both sides. Very thin coated papers are also knows as LWC (Light Weight Coated). Uncoated papers have no coating.

Art papers are high-quality papers coated elaborately on both sides for prestigious, color printing products. They have an even and smooth surface. These papers are available with matt, semi-matt and glossy qualities. Pictures of the highest halftone grades can be reproduced in letter-press offset. Illustration printing papers are coated, often also calendered (a process to make the paper smooth and glossy by running the paper through what essentially are polished steel rollers) and available in various quantities. Cast-coated papers (which can be identified by its high-gloss, mirror-like finish and superior smooth surface) and cards are especially glossy.

There are also other varieties of paper, such as board, cardboard, varieties of hardboard (used for book covers) and special papers such as, parchment papers, carbon-copy, WP papers (made out of 100% waste papers), and fine papers (which are usually the best quality paper). Fine papers often have watermarks and are very firm on the surface with even opacity which leads to a very good quality printing. High-gloss papers are cast-coated but not calendered. Chromium papers (most suitable for offset printing) have watertight coating. Colored papers are tinted, varnished and patterned. Vat papers are handmade papers with a typically uneven edge. Japan papers – also called “washi” (literally means Japan=’wa’ paper=’shi’) which are made from native Japanese plants such as kozo, mitsumata, gampi and kuwakawa and are most commonly used in printmaking.

Paper by use:

  • Offset papers – woodfree and wood-containing uncoated papers as well as uncoated recycled paper in calender or machine finishes.
  • Magazine papers – also art papers – are uncoated, usually wood containing, calendered papers with a high proportion of filler that are particularly good at reproducing pictures.
  • Laser printing papers – have an even, especially prepared surface to ensure the best possible toner adhesion and to support an instant electrical surcharge of the printer.
  • Inkjet printing papers – with surfaces finished for rapid absorption of the ink. They help prevent the ink from running.
  • LWC – lightweight papers, thin and coated used mainly for web offset (printing on sheets of paper rather than a roll) printing for magazines and catalogs.
  • Digital papers – have variety f capsules or spheres embedded in the paper filled with dyes and white particles that create various surface affects after the press run.

The main paper types under ISO 12647 standard:

  • Glossy coated (paper class 1)
  • Matt coated (paper class 2)
  • LWC papers (paper class 3)
  • Uncoated papers (paper class 4)
  • Uncoated yellowish papers (paper class 5)
  • Newsprint

Almost every print-shop has print and paper samples for customers to showcase their paper selection and how it interacts with their press. Below are examples:

http://www.thepapermill.com/digital.html

http://www.printingforless.com/samplesrequest.html

Checklist: Choosing paper

  • What effect is intended?
  • How is the paper to be used?
  • How long does the paper have to last?
  • How much can the paper cost?
  • What printing process is to be used?
  • How is the printing product to be handled afterwards?

Surface Finishing:

The varnishing process takes place at the last stage of print. It is an application of a colorless, glossy- or matt- drying layer of varnish. This is either done as print varnish in the press, or as a water-based emulsion varnishing using a special machine. Varnishing is mostly used on covers of the finished projects. Varnishing protects the surface and enhances the abrasion resistance of printing inks. There are a variety of varnishing methods available:

  • Shadow or spot – only specific areas are varnished; varnish acts as a spot color. Planned image varnishes receive more varnish than the rest of the page.
  • Effect varnishes – special varnishes used to achieve specific effect. They consist of pigments with articles of varying colors, shapes and sizes.
  • Water-based varnishes – usually applyed in varnishing machine. It is not as glossy as other varnishes.
  • Fragrant varnishes – very specialized product and contains fragrances in micro-capsules which are released when varnished surfaces are rubbed.
  • Lamination – is a layer of transparent film of plastic applied to printed product to protect it.
  • Hot foil stamping – a thin layer of plastic applied under pressure instead of ink in the letterpress process. That surface is then etched or engraved with a layer of aluminum. Good example is a holographic coil.
  • Blind stamping – includes embossing (raised) or debossing (depressed). Does not necessarily contain ink.

 Binding:

Most common types of binding:

  • Stitched or stapled binding – the printed matter is bound to form a book block using thread or wire or staples:

  • Block stapling – trimmed sheets are fastened together on one side with staples.
  • Spiral, plastic, or wire-o-binding – are loose leaf binding systems. Stacks of paper are punched at one side and appropriate binding inserted:

  • Perfect or threadless binding (block gluing)- the spine of the block is trimmed to produce individual sheets, which are then bound with adhesive. Another form is fan binding where pages are fanned as the glue is applied and then clamped with glue applied again. The process then repeated on both sides of the book. This produces more hold for individual pages then perfect binding. Also includes tape-binding where glue is applied to a tape on top of the perfect binding to hold the book together more securely.

  • Hardback binding – the cover is fastened directly to the back of the block using gauze  and endpapers. The book can also be finished with a decorative band and a ribbon bookmark.

Further Resources: