The Ricoh G5 and G6 are both widely discussed industrial printheads, but the G6 is not simply a faster and more precise replacement for the G5.
The G6 uses smaller droplets and supports a much higher firing frequency. That can improve fine details, but it also places greater demands on the printer’s ink supply, mechanical accuracy, cooling, and control system.
So, which one is better?
The answer depends on what you print and whether the complete machine is properly designed for the Printhead.
Droplet Size and Color Blocks
The Ricoh G6 is officially known as the MH5320.
Its standard droplet size was reduced from approximately 7 pl on the G5 to 5 pl on the G6. The larger droplet also dropped from around 21 pl to 15 pl.
Smaller droplets can create smoother transitions and improve fine image details. This is one of the main advantages of the G6.
However, smaller droplets can also create problems when printing large solid-color areas.
Under the same pass settings, the G6 may produce slightly weaker coverage and less uniform color blocks than the G5. In some real-world applications, simply increasing the number of passes does not improve the uniformity in a linear way.
In other words, adding more passes is not always enough to fix uneven solid colors.
The machine also needs better mechanical accuracy, stable ink output, and optimized printing control.
Small Droplets and Print Distance
Smaller droplets lose speed more quickly while traveling through the air.
At the same printhead-to-media distance, the G5 droplets may land more accurately than the smaller G6 droplets.
This can affect the depth and three-dimensional appearance of the printed image. In some situations, the G5 may produce a stronger visual result.
To get the best detail from the G6, the distance between the printhead and the material should usually be kept smaller.
A larger gap gives the smaller droplets more time to drift. Air movement around the carriage can also affect where the droplets land.
This means a G6-equipped printer needs:
- Better control of the print gap
- More stable carriage movement
- Less airflow around the printing area
- Higher mechanical accuracy
- Better droplet-positioning control
The G6 can produce very detailed images, but only when the machine is accurate enough to take advantage of the smaller droplets.
Ink Supply Requirements
The G6 requires a much higher ink flow when operating at its maximum firing frequency.
At maximum output, the estimated ink demand is approximately:
- G5: 33 ml per minute
- G6: 57 ml per minute
That is a major increase.
A supply system originally designed for the G5 may not provide enough flow for the G6.
The manufacturer needs to confirm that:
- The pumps provide enough flow
- The ink lines are large enough
- The filters do not create excessive pressure loss
- The negative-pressure system remains stable
- The dampers respond quickly enough
If the firing frequency increases but the ink supply cannot keep up, the printer may experience ink starvation, missing nozzles, or sudden interruptions during printing.
The G6 should not be installed as a simple drop-in upgrade without checking the entire supply system.
Printhead Cooling
A higher firing frequency also creates more heat inside the printhead.
As the piezoelectric elements fire more frequently, the internal temperature rises. Excessive heat can affect droplet formation, jetting stability, and overall print quality.
A G6-based machine therefore needs better cooling around the carriage and printhead area.
The machine design should consider:
- Airflow
- Heat dissipation
- Operating temperature
- Long production runs
- Temperature changes inside the printhead
A printer may perform well during a short test but become unstable after running continuously if the cooling system is not adequate.
Ink Requirements
The G6’s higher firing frequency also places stricter requirements on the ink.
Many ink manufacturers mainly test static viscosity and surface tension. Those values are important, but they do not show how the ink behaves when it is exposed to high-frequency shear inside the printhead.
At higher firing frequencies, the ink must maintain stable flow and droplet formation.
This means the ink needs to be tested for:
- Dynamic viscosity
- High-frequency jetting
- Shear behavior
- Droplet speed
- Long-term stability
- Temperature sensitivity
The G5 has been on the market longer, so compatible inks are generally more mature.
The G6 may perform very well, but poor or insufficiently tested ink can prevent the printhead from reaching its expected speed and quality.
Mechanical Accuracy
The G6 can reach a firing frequency of around 50 kHz.
At 600 dpi in the carriage direction, the carriage speed may reach approximately 2.1 meters per second.
That is very fast, and it creates much higher mechanical requirements.
For acceptable image quality, the ratio between the carriage speed and droplet-fall speed should generally remain above approximately 1:4.
At a print distance of about 1 mm, the G6 droplet speed is normally around 6–7 meters per second.
At 600 dpi, the carriage may move too quickly to maintain the desired ratio. Printing at 720 dpi can reduce the horizontal travel speed and improve droplet placement.
Using 600 dpi may still be acceptable for customers with lower image-quality requirements, but fine details can suffer.
High carriage speed also creates another problem: acceleration.
The acceleration area cannot be too long, or too much printable width will be lost. The machine may therefore need acceleration greater than 1G.
That sudden movement can create pressure fluctuations inside the ink lines.
To keep the supply stable, the system may need:
- Pressure fluctuation absorbers
- More accurate negative-pressure control
- Better dampers
- Stable ink lines
- Faster pressure compensation
The G6’s performance depends heavily on the mechanical and fluid-control design of the printer.
Firing Frequency
Although the G6 can reach a very high maximum firing frequency, the highest setting is not always the most stable setting.
Based on repeated testing, a firing frequency of around 35 kHz appears to be a relatively stable working point for many applications.
When the frequency is increased beyond that point, droplet speed may begin to fluctuate.
To operate reliably at a higher frequency, the manufacturer may need to further optimize:
- The waveform
- Ink supply
- Negative pressure
- Carriage motion
- Mechanical accuracy
- Cooling
- Ink chemistry
A high maximum frequency looks impressive on a specification sheet, but the stable production frequency matters more in actual use.
Ink Compatibility
One major advantage of the G6 is its broader ink compatibility.
Compared with the G5, the G6 can support a wider range of ink types, including:
- UV ink
- Reactive ink
- Pigment ink
- Disperse ink
This allows the G6 to serve more industries and applications.
However, compatibility still depends on the exact printhead configuration, waveform, supply system, and ink formula.
The fact that a certain ink type is supported does not mean every brand or formula will work correctly.
Always use ink tested for the specific printer and printhead configuration.
Which One Is Better?
The G5 may be a better choice when you need:
- Mature ink compatibility
- Stable production
- Strong solid-color coverage
- Reliable droplet placement
- Less demanding mechanical requirements
- A proven printing system
The G6 may be a better choice when you need:
- Smaller droplets
- Finer image transitions
- Higher potential firing frequency
- Broader ink compatibility
- Greater production potential
- A newer industrial platform
However, the G6 only delivers its full value when the printer has been designed around it.
Installing a G6 on a machine with an old ink supply system, weak mechanical structure, poor cooling, or inaccurate negative-pressure control may create more problems than benefits.
Conclusion
The Ricoh G6 offers smaller droplets, a higher firing frequency, and broader ink compatibility than the G5.
These improvements can produce finer details and higher output, but they also create stricter requirements for the entire printer.
The G5 remains a mature and stable choice. It can provide stronger solid-color coverage, reliable droplet placement, and easier system integration.
The G6 has more potential, but it needs:
- Higher ink flow
- Better cooling
- More accurate mechanics
- Stable negative-pressure control
- Proper high-frequency ink
- Optimized firing settings
So the real comparison is not just G5 versus G6.
It is a mature G5 printing system versus a properly engineered G6 printing system.
A well-designed G5 machine may perform better than a poorly designed G6 machine. Before choosing, look beyond the printhead specification and evaluate the complete printer.