The most common paper sizes – especially in the Greek market – are 61x86cm and 70x100cm. There are other sizes too, but those two are the most common ones and therefore the cheapest.
The 61x86cm size is called A and there are:
A1:59x84cm* A2:42x59cm* A3:42x29cm* A4:21x29cm* A5:14.5x21cm* A6:10.5×14.5cm*
The 70x100cm size is called B and there are:
B1:68x98cm* B2:48x68cm* B3:34x48cm* B4:24x34cm* B5:17x24cm* B6:12x17cm*
(*Later we’ll explain why there are some centimeters missing from each size.)
All offset printouts are printed on paper of these sizes. In order to find the right size for our printout, all we have to do is divide the aforementioned sizes to create the shape we need.
However, there are some things we should be aware of:
Machines need to grip the paper on some spot and this spot (gripper edge) cannot be printed. We have to leave this area out of our size estimate. The gripping edge is always on the full-size paper (and deducted from the small sizes) from 1.2cm to 1.5cm. If our project is to be printed on a blanket-to-blanket machine, the gripping edge is 2.5cm because the machine grabs the paper from both sides.
When using the 61x86cm paper, the final product after the gripper edge deduction is 21.5×29.7cm (61-1.5=59.5/2=29.7, 86/4=21.5)
After the deduction of the bleed edge (mentioned on a previous post), the printable size of our printout after it’s cut will be 21x29cm (A4). If we’re going to print on a blanket-to-blanket machine, it will be 20.5×28.5cm. Even if we want to print full size, the dimensions will be 59x84cm. It could theoretically be 59.5x86cm, but offset printers cannot easily spread the colour till the paper edges, when the background bleeds. So we should leave some white edges around the paper in order for all the technical tools of an offset machine to be easily used (cross-marks, colour bars, pliers, brushes etc). This way we can make sure that our printout will be as desired and the colours will be evenly spread. This also stands for the B size, where the 70x100cm size turns out to be 24x34cm (B4).
Of course, if we want to create innovative printed media (like rectangular or square), we can divide the aforementioned dimensions differently.
If we don’t work this way there will be left over paper. However, we can always use any shape we want regardless of whether it is economical or not. When it comes to small runs, we shouldn’t be discouraged from proposing modern shapes even if they’re uneconomic. The paper that will be left over is very little.
However, if we’re talking about large runs, we should be more considerate when designing the shapes. Otherwise, there will be a lot of paper left over.
On the next post, we’ll talk about economical use of paper in the case of bindery.
Economical paper sizes for printed media