How to Master Colour Matching in Water-Based Printing Ink

In today’s packaging industry, brands demand colour precision, consistency, and sustainability. As printers shift from solvent-based to water-based ink systems, mastering colour matching has become one of the most valuable technical skills in any pressroom.

Unlike solvent inks, water-based inks are more sensitive to environmental and chemical variables — pH, viscosity, and drying rate all influence final print colour. 

For example, achieving a perfect match, such as Pantone 238 C, requires both science and craftsmanship.

Step 1: Start with the Correct Pantone Formula

Every spot colour begins with the official Pantone Formula Guide. For example, to reproduce Pantone 238 C (a bright red-violet tone), the guide lists the required base inks and proportions — typically a mix of Rhodamine Red, Violet, and Transparent White.

Since every ink manufacturer has its own base set, translate these Pantone bases into your supplier’s water-based equivalents — e.g., Rhodamine Red Concentrate, Violet Concentrate, and Extender.

Step 2: Weigh Accurately — Don’t Eyeball It

Colour accuracy starts with precise weight ratios. For a 100 g batch following the above formula:

• Rhodamine Red → 80 g

• Violet → 15 g

• Transparent White → 5 g

Use a digital balance accurate to ±0.01 g. Add darker inks to lighter bases slowly to prevent overshooting your target shade.

Step 3: Test and Evaluate

Once mixed, apply the ink to your actual substrate using a hand proofer or anilox proofer that mimics your press volume.

• Visual check: Compare the sample with the Pantone 238 C chip under D50 standard light.

• Instrumental check: Measure with a spectrophotometer and record the L* a* b* values. Aim for ΔE ≤ 1.0–3.0 for production tolerance.

Step 4: Control pH, Viscosity, and Environment

In water-based systems:

• Viscosity: 25–35 s (Zahn #2 cup), depending on the ink's performance

• pH: 8.0–9.5, depending on the ink's performance

A drop in pH reduces resin solubility, causing colour shift and poor transfer; viscosity changes can affect density and gloss. Check both every 30–45 minutes during a press run.

Humidity, temperature, and airflow also affect drying and colour appearance — consistency in these factors is critical for repeatable colour.

Step 5: Adjust with Precision

If your print deviates from target:

Always adjust in small, recorded increments and retest until ΔE is within tolerance.

Step 6: Document and Standardize

Once the colour is approved, record the final formula, substrate type, anilox volume, and press conditions. Store these in a digital colour database for future reprints. This ensures your next Pantone 238 C run starts right where the last one ended — saving time, ink, and waste.

The Modern Edge

New extended-gamut systems (CMYK + Orange, Violet, Green), combined with AI-based colour formulation software, now allow water-based printers to simulate Pantone shades faster and with tighter tolerances than ever before.

With disciplined process control and proper training, water-based ink can now deliver the same precision once thought possible only with solvent-based systems — while staying safer and cleaner for both workers and the planet.

Final Thought

Colour matching in water-based printing ink isn’t guesswork — it’s controlled chemistry backed by data. When your team masters this process, you don’t just reproduce colour; you reproduce trust, consistency, and brand integrity on every package.