1. How much ink does a plotter actually use?
2. Why one cartridge always runs out first — you are here
3. How much plotter ink should you buy?
A tank is per colour. Your prints are not. That single mismatch is why plotter ink orders go wrong more often than any other reason — and why “order one of each” quietly wastes money in almost every office that does it.
In part one we established that a plotter consumes ink per square metre, and that the figure ranges from about 0.35 ml/m² for a mono CAD drawing to 15 ml/m² for a photograph. This part answers the next question: when that ink comes out, which tank does it come from?
1. The mistake that costs the most: buying tanks in equal numbers
Here is the thing almost everybody gets wrong. A tank is per colour. Your prints are not.
A mono CAD drawing draws roughly 95% of its ink from one tank — matte black. The cyan, magenta and yellow tanks barely move. So an engineering office that orders one of everything ends up replacing matte black five times before the first yellow tank is half empty. That yellow will very likely reach its expiry date before it reaches the bottom.
Your own machine will tell you the truth: almost every wide-format plotter logs actual ink consumption per channel. Pull that report before you place a bulk order.
2. So how many prints does a tank really give you?
This table answers the question people actually mean when they ask "how long will a cartridge last". It counts A1 prints until the fastest-emptying channel runs dry — because that is the tank that stops your machine, regardless of how full the others are.
| Job type | Busiest channel | 130 ml tank | 330 ml tank | 700 ml tank |
|---|---|---|---|---|
| ■ Mono CAD line | Matte black | ~780 | ~1,990 | ~4,220 |
| ■ Colour CAD / dense line | Matte black | ~370 | ~950 | ~2,010 |
| ■ Map / site plan / render | Matte black | ~215 | ~550 | ~1,165 |
| ■ Poster / full-colour graphic | Cyan | ~110 | ~280 | ~600 |
| ■ Photo / fine art / backlit | Cyan | ~60 | ~155 | ~330 |
Halve these figures for A0, double them for A2. Common Canon imagePROGRAF tank sizes map onto these columns: 130 ml (PFI‑120 class), 300–330 ml (PFI‑310/320/340 class) and 700 ml (PFI‑710/740 class), with 55 ml entry tanks on the compact TA models.
Note the shape of it: a mono CAD office gets nearly 4,220 A1 plots out of a single 700 ml matte black. A photo studio gets 330. Same tank, same price, thirteen times the output — which is why "how long does a cartridge last" has no universal answer.
The buying guide itself — a two-step calculator that turns your volume and job mix into a three-month order, plus the four things that quietly eat ink and why a twelve-month buy is usually a mistake.
Want to know which tank is emptying first on your machine? Send us your monthly plot count and job mix and we’ll tell you — and quote only the tanks you actually need.
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Notes
Figures are built from published wide-format coverage thresholds. Channel splits, media multipliers and maintenance overhead are indicative planning figures, not manufacturer specifications — your own machine’s ink-usage log is always the better number.