D65 Light Source
The D65 light source is a standard lighting condition that imitates the color of average daylight, and is used as the reference light source when evaluating and comparing the colors of fabric and trims.
Contents6 sections
Definition and Overview
The D65 light source is a standard light set to reproduce the appearance of natural daylight. It is used for the purpose of checking colors of dyed swatches, fabric, buttons, zippers, and other items under the same conditions among people involved in planning, production, and inspection.
D65 is not a name that describes fabric weave structure, material, or texture. It is a lighting condition for checking how colors appear, and it does not indicate the functions of the material itself, shrinkage from washing, or sewing specifications.
Color Appearance and Features
When the type of lighting changes, the impression of hue, brightness, and vividness changes even for the same fabric. Matching colors under a D65 light source makes it easier to check colors in an environment close to daylight. It is especially important for checking subtle color differences in white, light colors, gray, blue shades, and beige shades.
The phenomenon in which materials that look the same color under different light sources appear to be different colors under another light source is called metamerism. When combining outer fabric and lining, different lots of fabric, or prints and accessories, it is important to check not only under D65 but also under lighting close to the actual usage environment.
Main Applications
In apparel, it is used for color matching during dyeing, checking lab dips, inspecting production rolls, incoming inspection, and comparing samples with mass-produced items. It is useful not only for fabric alone, but also for confirming color coordination including sewing thread, interlining, lining, prints, labels, and garment accessories.
It is not a light source limited to a particular season or item. It is used for a wide range of products that require color reproducibility and color matching, from light-colored clothing for spring and summer to dark-colored clothing for autumn and winter, uniforms, and formal wear.
Points to Note During Inspection
Color judgment is affected not only by the type of light source, but also by the brightness of the lighting, the angle of observation, the color of the surrounding walls and desk, and the condition of the observer. In color evaluation equipment, external light is avoided and the background and observation conditions are kept as consistent as possible.
Before sewing, check differences in appearance caused by cutting direction and nap. Shiny fabrics, brushed items, pile, and iridescent materials tend to change in color and shade depending on the viewing angle, so check them not only laid flat but also at angles close to actual use conditions.
Evaluation of discoloration or fading due to washing, friction, or sunlight must be checked separately from color matching under a D65 light source. Share the washing care instructions for the selected materials, colorfastness test results, and the color difference standards for the production lot in the specification sheet, and make the judgment conditions clear.
- Place the color sample and product in the same direction and compare them side by side.
- Take care with white and light-colored items containing fluorescent whitening agents, as their appearance can change depending on the lighting conditions.
- If a color difference is suspected, check under multiple light sources to confirm metamerism.
Differences from Similar Terms
Standard light source is a general term for standardized light sources used for color evaluation. D65 is one representative type, and artificial daylight is a general term used to refer to lighting that imitates daylight. However, the term artificial daylight alone does not necessarily mean the same conditions as D65.
A lab dip is a small dyed sample prepared before mass production. The D65 light source is the lighting condition used when evaluating a lab dip, and it is not a term that refers to the lab dip itself. Colorfastness is the durability of color against washing, light, and other factors, while D65 is a condition for observing and comparing color.
Frequently Asked Questions
If I check under a D65 light source, will the color look the same under any lighting?
Not necessarily. Depending on the combination of material and dye, colors may match under a D65 light source but show differences under store lighting or warm incandescent lighting. For products that combine outer fabric and accessories, also check under the expected sales and usage environment.
Can a D65 light source be used to judge color changes after washing?
It can be used as the observation condition when comparing color differences before and after washing, but it does not guarantee the color's durability against washing. Evaluate it together with test results such as washing colorfastness, and make the judgment with the sample's drying condition and lighting conditions aligned.
