Paper Grain: The Long and Short of It

That was a little paper humor, emphasis on 'little'.  Anyway, as I sat there watching my paste paper curl into a contorted mess whilst drying, it reminded me to talk about paper grain.

To keep things simple, paper has a grain.  It is made up of fibers, greater in length than width, and these fibers have settled into a more or less uniform alignment in a sheet of paper.  There is much, much more to be said about the types of fibers and methods of paper making.... but each of those factors will make for long posts, nay, for textbooks (yes, I have those textbooks and no, they aren't terribly exciting).

Paper grain is important because it has the potential to ruin any paper project you are working on.  Those fibers that make up the paper will absorb water and swell laterally.  So basically, the grain direction on a piece of paper is like an expansion joint.  The paper will expand/contract along this orientation as it experiences changes in moisture.  If you look at the drying paste papers (above), there is more curling along the length of the paper than the width because the grain is running along the length of the sheet.

You can clearly see the directionality and how paper always wants to do things along its grain when you tear a sheet of paper.

Most commercial papers are grain long, as in, the grain is running down the length of the paper.  When you tear it this way, it is very easy.

But when you try and tear it against the grain, it will want to self correct and run back with the grain.  I started tearing at the top of the sheet and the tear promptly took a turn.

So why does all this matter?

Well, if you put glue, decoupage medium, or just moisture from humidity on paper, you will get swelling and possibly wrinkles if you did not leave room (or just not attach down the far end of the sheet) for the expansion.  If you are making invitations and are mounting things, your invitations will be warped if you do not consistently layer things in a parallel grain direction.  If you are making a book, the grain direction is kept parallel to the spine because glue (i.e. moisture) is applied to the spine and this allows the pages to expand out without wrinkling.  Just something to keep in mind as you start a paper project.