Paper Grain Direction and Cardboard Grain Direction

We have a pretty thorough list of tutorials and bookbinding instructions here at iBookBinding.com. At least if you are interested in case binding and some non-adhesive types of bindings. Today we start posting new tutorials. Sometimes they would cover some very small steps of bookbinding process.

Paper and cardboard grain is something many novice bookbinders forget to take into consideration. Many types of paper have a distinctive grain direction due to their production processes. Paper consists of fibers of cellulose pulp (with or without some additives), pressed together while moistened. Direction of these fibers determines paper grain direction.

Grain Direction Marking

Paper manufactured by major producers usually has a long grain, that is to say, parallel to the long side of the sheet. Handmade paper and some other sorts and brands of paper may have short grain (grain parallel to the short side). Sometimes grain direction may be much less noticeable or even almost undefined.

Markings on the production packaging should help you finding the grain direction. There are several standard ways to mark the direction:

  • With words Grain Long or Grain Short.
  • Underscoring one of the dimensions: 10×15 means short grain, 21×7 indicates long grain.
  • Sometimes machine direction may be marked like this: 33,1M×46,8, which indicates short grain.
  • One more way to mark the grain direction is by ordering the dimensions. The last one gives you the dimension: for the 10×15 the grain is long, and 15×10 sheet has a short grain. That’s sort of an industry standard. Unfortunately, in case of long grain you would never know if the manufacturer forgot to mark the grain or decided to use that standard way of marking.

If there are no markings, you have to check the grain direction by experiment before proceeding to any further steps.

Wrong Grain Direction

It is very important to know the grain direction because paper and cardboard stretches and bends differently along and against the grain. In wet conditions (including glue application) paper products tend to wave (with curls going along the grain).

Wrong grain direction is often chosen for large print projects. Cutting a sheet of paper in the ‘wrong’ direction may save you up to 10% of paper or even more. However, wrong grain direction makes book less usable and even leads to structural damage and early deterioration:

  • When you turn the pages, they tend to bend a bit. If you have wrong paper grain direction, there is a higher chance of fractures or tears. Pages may also resist turning if the grain direction is wrong.
  • In wet conditions wrong grain direction may result in damaging the spine and braking the book structure. That can happen even during gluing or pasting the book.
  • Glue may penetrate along the grain direction from the spine inside the book block.
  • Book may not open properly if it is bound with wrong grain direction.
  • Pages may curl and flare, edges may become wavy.
  • Cross-grain layouts may also lead to problems (e.g. covers have grain direction that is different to grain direction of paper).
  • Folding paper with wrong grain direction (not going along the grain) may result in cracks and other damage to paper.

Grain direction should go along the spine. That remains the same for all the different elements of the book: pages (sheets), spine lining, endleaves, covers, and any other paper and cardboard materials you use. You should also mind the grain direction during other processes, like box-making.

How to Find Paper Grain Direction?

I will list five different ways to determine grain direction even while I prefer binding paper and cardboard to other methods:

  • Paper and cardboard offer noticeably more resistance in one direction than the other. That resistance comes from grain springing. Grain direction goes along the curve of least resistance. Method works well for thicker papers and cardboard, however you can try to apply it to a thinner paper.
  • Applying moisture to a side of paper, you will make it wave or curl. If the whole moistened side starts to curl upwards or downwards, that means grain goes along that side. If the side becomes wavy, grain follows perpendicular direction.
Determining grain direction by moistening a sheet of paper

Determining grain direction by moistening a sheet of paper

  • When you tear the paper against the grain, fibers do not allow the tear to go straight. Instead, you get a sort of zigzagged tear. Paper and cardboard also tend to flake when torn against the grain. Tearing along the grain gives you almost a straight tear.
  • When folding along the grain, you’ll get an almost smooth fold. Folding against the grain may result in cracks and even tears (depending on paper). That happens because fibers are aligned perpendicular to the fold and you break them folding the sheet.
  • Sometimes you can identify grain direction by the pattern of the material you use. That happens with some sorts of cardboard and Japanese paper.

Obviously, the last two methods make an irreversible damage to your material; therefore, they couldn’t be used if you have only so much paper or cardboard. For almost all my projects I prefer bending paper and cardboard.

That said, I’ll illustrate what happens with grain direction when you fold A4 (210 by 297 millimeters / 8.27 in × 11.7 in) and A3 (twice as large as A4) sheets. I suppose that A4 and A3 sheets usually have a long grain.

Out of a standard A4 piece of paper you may bind a book with page size similar to A6 (quarter of A4). But A5-sized (half of A4) quires would have a wrong grain direction.

To bind a book with dimensions similar to A5 you have to take A3 paper and fold it two times in quarter. Than the grain direction would be long once again.

As a bonus, here is a video by an Egyptian book conservator Sherif Afifi:

Good luck with your projects! And may the grain go in the right direction! =)