In the cutting room, if we want to speak a universal language, the information sent to cutting machines and spreading machines — whenever they need data related to the marker they are about to process — is, in most cases, provided in ISO format.
The ISO format is often simply called “ISO”, but in reality it originates from a very specific historical system: a language originally developed and codified by Gerber for the old S24 system.
Over time, this format has evolved, but its fundamental principles have remained the same.
The ISO file is what allows the CAD system to transmit operational instructions to the cutting machine, the spreader, and, if present, also to labelling systems operating within the cutting room.
In a future article, I will go into full technical detail about the ISO format. Here, instead, I want to focus on the basic concept.
Unlike plotters — which typically use a proprietary format, such as HPGL, developed by HP and also adopted by Lectra — ISO is an extremely simple language.
It is a plain text file that can be opened with any text editor. Inside, you will find a sequence of commands, and the number of commands actually used today is relatively small.
For example, when opening an ISO file, you will find instructions such as:
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M14: lower the blade (start cutting)
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M15: raise the blade (end cutting)
Between two asterisks (*), you will find the coordinates, which describe the path of the blade in space.
If someone were patient enough to take a pen, a sheet of graph paper, and follow all the coordinates line by line — perhaps using one colour when the pen is “down” and another when it is “up” — they could, in theory, reconstruct the entire ISO file by hand.
It would be a slow and impractical exercise today, but it helps to understand a fundamental point:
the ISO format is transparent, readable, and conceptually simple.
And this is precisely why it is so important to understand it.
ISO is the entry key that carries information from the CAD system to the cutting machines and, more generally, to all the equipment operating inside the cutting room.
Understanding ISO means truly understanding how machines communicate.