If you’re using paper at 250gsm grammage or above for products such as folding cards, flyers, and brochure covers, we’d recommend that you crease the paper where it will be folded. Should you opt for creasing or grooving and where’s the difference? Find out more below!
What is the use in creasing and grooving?
When you fold higher-grammage paper, the fibres at the edge of the fold can sometimes snap and, since folding is always done after printing, colour which has already been printed can crack and be damaged. In order to avoid this, we recommend creasing or grooving paper at 250gsm or above; both methods weaken the material at the fold and make the paper easier to fold, but are fundamentally different techniques.
In the paper industry, creasing refers to a way of changing the shape of the paper. In order to be able to fold a sheet more easily, the paper gets weakened along the so called “creasing line”, i.e. a channel is formed along the paper, which weakens its structure as the material is stretched all the way along the fold line. When the sheet of paper is turned over, the bottom of the channel score is visible as a thin linear elevation.
In the context of paper production, grooving is a machine-tool process, often referred to as v-grooving (or “veegrooving”) very much like in other materials work e.g. woodwork. A grooving tool removes a small amount of material from the paper, and the minimal loss of material along the fold line makes the sheet of paper weaker here and easier to bend and fold. Due to the fact that material is taken from the paper, this process should and can only be carried out on very high-grammage papers and cardboard.
In terms of printed products, creasing really is the only method recommended because grooving also removes the printed surface.
As well as offering an aesthetically more pleasing result on thick-paper products such as greetings cards, folded leaflets, or brochures with perfect binding, pre-defining folds has advantages in the process of folding itself: given that sheets of paper always fold at the point of least resistance, producing targeted weakness along a defined line is the best way to make sure that the fold actually takes place at this line.