Paint shade variation means the colour of one batch differs from another or from the approved sample. Colour variation in paint batches can come from pigment lots, weighing, dispersion, drying conditions or the way colour is compared.
Here you will find what happens in the batch, the usual causes, the checks that find the cause and the steps that correct it. Paint Manufacturing Machines guides manufacturers through each of these steps. It is also searched as colour variation in paint batches, paint colour matching problems and batch to batch shade difference.
We help your team set clear process steps and quality checks, so every batch is made the same way. For paint shade variation, process steps and quality checks are set with the technical team of IPCS (Indian Paints Consulting Service).
Understanding Shade Variation in Paint Batches
Colour is judged by the customer first. When shades differ from batch to batch, painters see a patchy wall, so colour control is one of the most important parts of paint manufacturing.
Colour also looks different wet and dry, and under different lights, so the same method of comparison must be used every time.
Common Causes of Shade Variation
Most causes fall into three groups: the formula, the process and storage.
Raw materials
- Differences between lots of titanium dioxide or colour pigment
- Tinter strength that varies between lots
Process
- Weighing errors in tinters, which are used in small amounts
- Pigment that is not fully dispersed
- Different mixing times
Comparison
- Wet paint compared with a dry standard
- Different lighting or substrate
Checks to Find the Cause
Work through the checks in order. Each check narrows down the cause.
| Check | What to look for |
|---|---|
| Tinter and pigment weights | Check against the recipe |
| Dry film comparison | Compare dried drawdowns with the standard |
| Pigment lot records | Look for a change of lot |
| Fineness of grind | Poor dispersion lowers colour strength |
| Lighting and substrate | Compare under the same conditions |
How to Correct and Prevent Shade Variation
Correct the cause found in the checks, then make the change part of your batch card so that it holds for every batch.
- Weigh tinters on calibrated scales, and use weight rather than volume
- Tint to the standard in small steps and compare dry films
- Use a spectrophotometer to measure colour difference where possible
- Blend batches or use a master batch where shade must match exactly
- Record pigment lots and compare with the previous lot
Quality Checks That Keep It Under Control
Regular tests show a change early, while it is still easy to correct.
- Dry drawdown against the standard for every batch
- Colour difference reading with a spectrophotometer
- Pigment lot checks on arrival
- Retained sample of every batch
How We Help With Shade Variation
From the first plan to regular production, our team works with IPCS on layout, machines, formulation, quality control and training.
- On-site or remote review of your formula and process
- Raw material and equipment checks
- Trial batches with the proposed correction
- Updated batch cards and operator training
- Ongoing technical support after the correction
Frequently Asked Questions About Shade Variation
Why does paint colour differ between batches?
Pigment lots can vary, tinters are used in small amounts, and mixing and comparison conditions can change. Weighing and method control reduce the difference.
What is colour variation in paint batches?
It is a difference in colour between batches or against the approved standard, seen when films are dried and compared.
What are paint colour matching problems in a plant?
They come from lot differences, weighing errors, wet-versus-dry comparison and different light. Matching dry films under the same light helps.
How to control shade in paint manufacturing?
Weigh tinters accurately, control pigment lots, tint to a standard in small steps and compare dry films under the same light.
What is a batch to batch shade difference?
It is the colour difference between two batches of the same shade, measured visually or by a spectrophotometer.
What causes colour matching tinting problems?
Tinter strength differences, base paint differences and comparing wet paint with a dry standard are common causes.
Is a spectrophotometer necessary?
It is not necessary at the start, but it gives a number for colour difference and helps larger plants.
Get Technical Support for Your Paint Batch
Send us your product, batch size and the result you see. We reply with a review of likely causes and a plan for correction.