Pigment Red 112 for Printing Inks: What Formulators Should Validate Before a Trial

Define the Question the Trial Must Answer

A printing-ink trial should answer a specific technical question rather than a broad question such as "Does PR 112 work?" The first step is to define the printing process and the ink system in which the pigment will be evaluated.

For MANALI RED 111217, the supplied technical data identifies the material as Pigment Red 112 and describes it as a Naphthol AS pigment. The TDS lists applications including decorative paints, water-based paints, textile and dispersions. These application references do not, by themselves, establish suitability for every printing-ink system. [1]

The trial brief should therefore identify the printing process, binder or vehicle family, substrate, end use and the decision that the trial is intended to support. The decision may concern whether the candidate can be taken forward for a particular formulation and process after comparison with the approved control.

The broader Organic Azo Pigments technical hub provides category context, while the Organic Azo Pigments page is the relevant product-category route for a sample request.

Pigment identity should also be kept separate from commercial-grade identity. CI Numbers and Technical Reference can identify the CI reference, but the commercial trial must use the exact MPPL grade: MANALI RED 111217.

Lock the Formulation and Process Inputs

Define the vehicle

The binder or vehicle is a trial variable that must be identified before evaluation. Water-based, solvent-based and other ink systems can impose different dispersion, viscosity, drying and application requirements. Identify the system being tested rather than treating a generic formulation as universally applicable.

The supplied water-based ink testing method provides a controlled preparation method for a water-based emulsion. It specifies pigment, emulsifier, dispersing agent, silicone defoamer, water and glass beads, followed by a defined shaking sequence. Those quantities belong to the approved method and should be used only within its applicable scope. [2]

Fix pigment loading and formulation basis

Pigment loading must be defined on a stated formulation basis before a comparison is made. A candidate and its control should not be judged from preparations made on different bases because the resulting shade, strength or flow observations may not be directly comparable.

The trial record should identify the pigment loading basis, total formulation basis and any permitted adjustment. Do not change the formulation after seeing the result unless the change is documented as a separate trial condition.

Record dispersion equipment and time

Dispersion conditions should be fixed and recorded because equipment, energy input, time and sequence can affect the state of the prepared dispersion. The trial record should capture the equipment used, operating conditions, processing time and any relevant temperature or pass information specified by the approved method.

For the supplied water-based method, the preparation includes glass beads and a defined shaking sequence. The method also defines separate preparations for mass tone and tint tone evaluation. These controlled preparation details should be retained in the laboratory record. [2]

Control viscosity adjustment and addition order

Fix the addition sequence before preparation and record when each component is introduced. Document any dilution or viscosity adjustment and apply the same agreed measurement stage to the candidate and control.

Viscosity should be evaluated under equivalent conditions for the sample and control. The approved Ford Cup procedure requires a calibrated cup, controlled temperature, valid flow-time readings and a consistent measurement procedure. Three valid readings are taken and the mean flow time is recorded. [3]

Ford Cup seconds represent flow time, not cP. Where an applicable cup-specific relationship is used, report the converted quantity and units separately; flow-cup documentation describes conversion to kinematic viscosity in centistokes. Any dilution or viscosity adjustment should be recorded rather than treated as an undocumented correction. [6]

Choose the Comparison and Observations

A comparison requires a current approved control with a known identity and status. For MPPL, the approved reference definition identifies RED 111217 as the reference standard used as a benchmark for quality and colour matching. "Same as STD" means the current batch matches the RED 111217 reference; "Comparable" means equivalent or comparable in quality and colour to that reference. [4]

The sample and control should be prepared and evaluated under equivalent conditions. The comparison can then be structured around the observations required by the approved method.

For colour evaluation, the supplied documentation distinguishes full tone and tint tone. The completed COA for MANALI RED 111217 records both as "Same as STD." The supplied water-based method also defines mass-tone and tint-tone preparation. Where the laboratory trial uses an automatic applicator and drawdown, the drawdown conditions should be controlled and recorded in the approved trial record rather than assumed from the pigment identity.

Opacity or transparency should be evaluated only where the approved method calls for it. The completed COA records opacity as comparable to the approved standard. [5] Likewise, flow or viscosity should be compared using the approved measurement method and equivalent test conditions.

The purpose is to separate an observation from an acceptance decision. "Same as STD" or "comparable" is a controlled comparison outcome; it should not be expanded into a general claim of universal printing performance.

For supporting technical documentation, see the quality documentation route.

Set Acceptance Criteria Before Evaluation

Acceptance criteria should be defined before the candidate result is reviewed. Each criterion should identify the method, unit or comparison basis, tolerance where applicable, approver and final disposition.

The following table distinguishes method-based comparison records from the specific batch-quality entries in the supplied documents. The final two rows are COA records, not automatic printing-ink acceptance criteria. For the trial itself, use the agreed method-specific criterion rather than an assumed numerical limit.

The completed COA for MANALI RED 111217 also records volatile matter, water solubility, oil absorption, Hegman gauge, residue on sieve and other quality observations. These are product-quality records and should not automatically be presented as printing-ink trial acceptance criteria unless the approved trial method assigns them that role. [5]

Interpret a Failed or Ambiguous Result

A result that does not match the control should not automatically be attributed to the pigment. Possible causes can arise from sample identity, preparation, formulation, dispersion, application or measurement.

The first response should be to verify that the correct commercial grade and control were used and that the comparison conditions were equivalent. The laboratory should then review preparation records, equipment, measurement conditions and any permitted formulation adjustments.

For viscosity, invalid Ford Cup runs should be rejected and investigated, and valid repeat readings should be obtained according to the approved measurement procedure. The method requires three valid readings for the reported mean and calls for investigation of invalid runs. [3]

For shade or tone differences, the trial record should distinguish an observed difference from the reason for that difference. A controlled repeat or escalation should follow the approved internal trial rule. Use the repeat count and exception authority documented in the applicable method.

The objective is a traceable decision: proceed, repeat, investigate or escalate, with the reason recorded.

Convert the Result Into a Supplier Discussion

An ink formulator sending a sample request or technical-data request should provide enough non-confidential information for the grade to be assessed in the intended application. A useful technical brief includes:

• Exact printing process.
• Binder or vehicle family.
• Substrate.
• End use.
• Pigment loading basis.
• Dispersion equipment and conditions.
• Viscosity or rheology target where relevant.
• Current control/reference.
• Required observations and acceptance criteria.
• Destination-market requirement only when applicable and verified.

For MANALI RED 111217, the control should be identified clearly as the approved RED 111217 reference where that is the intended comparison basis. If the customer needs a shade or performance match to another commercial pigment, the exact reference, application and comparison conditions should be stated.

Share only the non-confidential information needed for the enquiry. Do not disclose customer names, contact details, prices or confidential commercial information without authorization. The complete guidance on this page is available without registration; requesting a physical sample is optional.

Frequently Asked Questions