When artists are seeking out a new color to put on a canvas, they tend to gravitate towards machine mixed paint from manufacturers they trust. While in many cases, handmade items are in high demand, in artist-grade oil paint the opposite is true. Machine-mixed paint, as opposed to hand mixed, offers a far superior result because the product is thoroughly crushed and combined, and the color is consistent across the manufacturer’s line of products. Expert use of technology creates the difference in quality in every step of the creation process; machine rollers provide an even texture from the pigment, chromatographers ensure color purity and emulsifiers thoroughly combine the necessary ingredients, and spectrophotometers can be used to manage quality control.
Ultra-fine and artist-grade quality paints are not for simple hobbyists. The individuals who purchase these paints are typically professional artists who will be displaying their projects in public.1 Machine-mixed oil paint is ideal for these individuals, as the results are durable, consistent and predictable. As a result, artists tend to stick to a specific brand of paint, as they know they can trust that manufacturer to offer a certain outcome. Manufacturers that wish to stay—or become—these trusted suppliers gain that trust through guaranteeing their products with spectrophotometric color measurement in order to ensure accuracy and consistency.
Color Consistency Challenges in Oil-Based Paint Production
The creation of oil paint has changed significantly since the Middle Ages when these types of paints first came into popularity.2 During that time, artists created their paints in the studio. They’d purchase base pigments at apothecaries and mix them with vegetable oil, gums, resins, and other materials needed to create a workable color, mixed from recipes passed down from generation to generation. However, mixing oil paint was a time-consuming process made even more difficult by the lack of materials available, meaning that rarely could the artist create the same color twice. Mid-nineteenth century improvements in both technology and chemistry provided mass-produced paint for artists who wanted a superior, more predictable product.
Even today, with all our technological advances, it can still be difficult to ensure a consistent color every time. There are a number of variables that will impact the result of oil paint, including:
- Particle size: The base pigment size will influence the outcome, as colors tend to get lighter when pigment is finely ground and darker when particles are left larger.
- Oil types: The oil base of the paint will have a direct impact on that paint’s luster, opacity, and brilliance. Many different oils are used in the production of oil paint; linseed, sunflower, and vegetable oils are just a few examples. The oil type will also affect drying time as well as the painting’s longevity.
- Additives: Additives are usually the secret twist that makes a manufacturer’s formula unique. Anything from resins to waxes to additional pigment can be used to change the end color, the texture of the end color, and how long it takes for the paint to achieve its final result.
- Mixing process: How the paint is mixed is as important as the components themselves. Machine-mixed paint tends to be better overall than hand-mixed due to the machine’s ability to finely grind powder. It also makes for less expensive paint, as mass production offers better profit margins, even with expensive pigments. Finally, machine mixing allows for greater color variety, as many large batches can be mixed at once rather than being limited by a laborious, small-batch hand-mixing process.
By using the same ingredients, equipment and methods, manufacturers can almost guarantee the color of their paints. By integrating spectrophotometric color measurement throughout the process, manufacturers can take their oil paint’s quality to the next level while minimizing waste.
Adding Spectrophotometers to the Oil-based Paint Mixing Process
Due to the high risk of color fluctuation in the oil paint creation process, top-level quality control is needed. Accounting for color change in this creation process is crucial to ensuring an accurate and consistent result that will meet the expectations of artists.3 As such, spectrophotometric color measurement is instrumental at various points of oil paint manufacturing, including:
- Starting pigment: Unprocessed pigment should be tested before use to ensure it matches to prior pigments. Base pigments can vary quite a bit based on a variety of factors, so early testing is imperative to detect unwanted color differences.
- After grinding: Grinding of the mill base, which includes pigment, a wetting agent, oil, and resin, creates a powder that greatly impacts the end color of oil paint. Measuring the color of this powder prior to mixing is an important step to ensure accurate coloration.
- After mixing: In order to make ground powders into functional paints, they are mixed with antifungals, antiseptic, driers, and stabilizers. During this process, the paint will be adjusted to match the manufacturers previously established colors based on ratios of mill base to additives and spectrophotometric data can be used to determine which adjustments must be made. This data can also be used to correlate color to mixing variables to catalog formulation for future use.
- When dry: After paint is mixed, test samples should be painted on swatches and analyzed for color correctness. Using a spectrophotometer, the analyst can evaluate the color, measure the results against prior tests, and note any variances in the process.
By incorporating color quality spot checks in the oil paint production process, manufacturers can ensure ideal color results every time. This not only helps to build trust between you and the artistic community, it also allows artists the ability to realize their vision and create works that may speak to audiences for generations.
HunterLab has been a pioneer in color measurement technology for over 60 years. Today, we offer a comprehensive range of portable, benchtop, and on-line spectrophotometers designed to meet the diverse needs of our customers. Our instruments are ideally suited for color analysis at every stage of the oil paint production process, giving you the highest level of color quality control. Contact us for more information about our renowned products and how we can help you improve color precision.
- “Manufacturing Oil Paint.” http://www.trueart.info/?page_id=50 ↩
- “Traditional Oil Painting: The Revival of Historical Artists’ Materials.” June 6, 2013. https://www.naturalpigments.com/art-supply-education/traditional-oil-painting-revival/ ↩
- “How Paint is Made. http://www.madehow.com/Volume-1/Paint.html ↩