It's a common misconception that humidification is only necessary during the autumn and winter seasons.
In fact, humidity control should be considered whenever certain environmental or production signals appear, regardless of the season.
If your facility doesn't have a temperature and humidity monitor, here's how to identify when humidification becomes essential:

1. When Obvious Production or Quality Issues Occur

This is the most direct indicator.
If your workshop experiences the following problems, there's a high probability that the humidity level is too low:

(1) Frequent Static Electricity Issues (the most prominent signal)

• Material adhesion: Printing media such as paper, PP film, or banner fabric may stick together, causing feeding errors, multiple-sheet intake, or jams.

• Dust attraction: Print media easily attract airborne dust and fibers, leading to white spots or blemishes on finished prints.

• Operator shocks: Staff frequently experience electrostatic discharge during handling.

• Ink misting or drift: Printed images show ghosting, blurring, or ink scatter due to static interference affecting the ink droplet trajectory.

(2) Abnormal Ink Drying Behavior

A. Overly fast drying (for water-based inks):
When ink dries before fully leveling or wetting the substrate surface, it can lead to:

• Increased risk of printhead clogging due to dried ink residues.

• Color deviation: Pigment buildup from excessive evaporation results in dull or inaccurate colors.

• Ink misdirection: Dried particles at the nozzle edge alter droplet direction, causing banding or overspray.

B. Overly slow drying (for UV-curable inks and non-absorbent substrates):
Although UV inks cure under ultraviolet light, low humidity can reduce ink leveling before curing.
Conversely, excessive humidity may cause condensation on the substrate, weakening ink adhesion.
Stable humidity is therefore crucial for consistent UV printing results.

(3) Material Deformation

• Mainly paper-based substrates:
  In overly dry conditions, paper loses moisture and curls, leading to:

• Misregistration: In multi-pass or multi-color printing, warped substrates cause color misalignment.

• Head strikes or wrinkling: Uneven media surfaces may touch the printhead, resulting in nozzle damage and print defects.

2. Preventive Humidification Based on Environmental Conditions

Proactive humidity control—before problems occur—is a more advanced form of production management.
Activate your humidification system when the following conditions apply:

(1) Seasonal Dryness

In autumn and winter, especially in northern regions, low atmospheric moisture and indoor heating drastically reduce relative humidity (sometimes below 20%).

(2) Continuous Air Conditioning

Most air conditioning systems dehumidify while cooling, significantly lowering workshop humidity.
A truly stable constant-temperature and constant-humidity environment requires integrated humidification.

(3) Geographic and Climate Factors

Workshops in inland dry regions require year-round humidification more often than those in humid coastal areas.

3. Humidification Requirements for Specific Production Processes

Certain printing applications demand strict humidity control:

(1) When Printing Static-Sensitive Materials

Materials such as PET, PE, PVC films, premium photo paper, or synthetic paper generate static easily.
Maintaining humidity between 50%–60% RH helps suppress static buildup effectively.

(2) For High-Precision Printing

Applications like art reproduction, fine photo printing, or color proofing require stable humidity to ensure consistent color and detail accuracy.

(3) Depending on Ink Type

• Water-based inks: Highly sensitive to low humidity, requiring humidification to prevent nozzle drying and ink evaporation.

• Latex inks: The curing process involves heat and ventilation, which can dry the environment—thus, humidity must be carefully managed.

💡Pro Tip

Equip your inkjet printing workshop with an accurate temperature and humidity monitor, and include it in daily inspection routines.
Maintaining an environment of 20°C–25°C temperature and 40%–60% relative humidity helps minimize environment-related production issues, ensuring consistent print quality and optimal efficiency.