What Is A Plotter?

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November 28th, 2018
Jason Tzintzun

One of the first questions I had while on the job was, "What the heck is a plotter?" It's one that I still get from family and friends when I tell them what I'm doing these days.

Prior to working at Source Graphics, I never gave much thought to how architecture and construction companies produced their work. I knew that plans were involved at some point in the process. But how they actually got to that point was, until recently, a complete mystery to me.

If you search "construction" or "architecture" on a stock image site, chances are you'll see an office with a set of plans on a table or rolled up somewhere in a corner. Or maybe two or three people bent over looking down at them. Those plans didn't manifest themselves out of thin air.

That's where a plotter comes in.

In short, the term "plotter" comes from the old pen plotters that were designed to save companies time and money. Before plotters were a thing, you'd have a whole room dedicated to drafters sitting at a table drawing out architectural and construction designs using triangles, compasses, rulers, etc. Of course the size of that room and the number of drafters depended on the size of the company.

But you can imagine how much time it took to craft multiple pages, multiple sets of those pages...and what if a change needed to be made halfway through??

Early pen plotters had pens mounted to a bar that traveled on an x and y axis. Drafters used computer programs such as AutoCAD, SolidWorks or Revit to tell the pen exactly what to do on the page. Compared to having a room full of people drawing all day, this was a huge advancement.

Nowadays, large format plotters/printers are often ink or toner based. There's no longer a pen plotting each drawing out, but a printhead (or multiple printheads!) that reproduces the design. Drafters can make changes easily in AutoCAD, design multiple layers in different colors, print multiple sets all at once.

And they are FAST, some printing up to 30 D size (24" x 36'") sheets per minute.

So that's what a plotter is: a large printer capable of printing architecture and engineering drawings. Some are 24 inches, some have integrated scanners, and some can print in full color, while others only in monochrome.

There's a whole world that was previously unbeknownst to me surrounding wide format printing. I hope I was able to peel back the tiniest sliver of that world for you.