About 50% of the time when I ask a customer “What stock would you like this on?” the answer I get is “Whatever you think it will look best (or print best) on.” I always wonder if they imagine a paper storage room with papers that print well on one side and papers that don’t on the other. Sometimes, I think it would be a lot easier if we stocked only one or two kinds of paper. But we don’t.
In the often confusing world of digital printing, paper weights and types have managed to distinguish themselves as a confusing topic for most people. Part of the problem lies in paper’s greatest drawback; it is a tactile product. Talk about it all you want; write long, complicated descriptions that start to sound a little like how a wine taster describes a wine; give it a brightness number. In the end, people want to FEEL the paper. And yet, this is also paper’s greatest asset, the reason it will probably survive the rush to a digital world. Paper has texture. Paper has a glossy or a smooth or a rough surface. It has depth. It has warmth.
In general there are only a few “rules” about what to print on, and these are very pragmatic. Things going through the mail need to be a certain minimum weight. No big surprise here. I have never had anyone try to send a post card that was printed on a text weight. Yet. BRC’s (business reply cards) must be a certain minimum weight. But aside from these few considerations, paper choice is a matter of taste and design. We try to stock a broad enough range of paper to meet most of those considerations.
Many US paper mills are no more. A good deal of our paper is from Canadian mills, some is from overseas. By the time it’s re-cut, re-branded, re-packaged and re-sold, it’s not always clear who actually manufactured it. Paper can be the cause of huge headaches in the digital print business. Humidity, too much or too little, can cause paper to jam unexpectedly, double-sheet feed, or curl out of the press. We keep most of our paper in sealed packs until we’re ready to use it. (We used to keep all of our paper in sealed plastic bins… the technology has gotten better.) We are very reluctant to add a new paper to our inventory until we have performed extensive testing. Sometimes, a rep (or a customer) will bring us in a few sample sheets which seem to run fine. Then when we begin the larger project, we suddenly experience multiple problems as the device heats up, or we try to duplex, or in finishing.
Most paper has some kind of a grain. In traditional (ink on paper) printing, the grain is usually “long” which means it runs parallel to the direction of the movement through the press (or is parallel to the longest side of the cut sheet). This gives the paper extra strength to navigate the many turns and twists through the press. In general, in digital printing, we like for the grain to be short so the sheet is more flexible. Grain is much more important when you get to finishing.
There are a couple of ways to check the grain. The easiest is to look at the packaging. The direction of the grain is usually the second number you see. 8-1/2″x11″ paper is long grain. 11″x8-1/2″ paper is short grain. (We speak of 12×18 as a stock paper size, but the package says 18×12.) If the paper is loose, fold the sheet you have in half in both directions and feel the folded edge. Folds with the grain will be much smoother than folds against the grain. I know there are other ways; tearing the paper will reveal its grain, but I think this is a bit more difficult to discern.
Grain comes into play more when you are finishing; folding, scoring, etc. Folding across the grain leaves a ragged edge unless you score first. For some paper weights, you need to score anyway, but especially in the lighter weight texts, trying to keep the grain going in the right direction when you are step and repeating a file can be the subject of some serious mental calisthenics. Scores across the grain need to be different than scores with the grain.
Next: paper weights and surfaces.