Metamerism

Definition and Overview

Metamerism is a color-appearance phenomenon caused by differences in the spectral reflectance characteristics of dyes, pigments, and similar materials. Color differences may become noticeable in environments with different spectral distributions of light, such as daylight, store lighting, warm-white or cool-white LEDs.

The weave structure, thickness, gloss, and surface fuzz of textile can also affect appearance, but metamerism itself is not a term for a specific material or type of fabric. It can also be an issue with combinations of textiles and accessories that appear to be the same color.

Effect on Appearance

Body fabric, lining, sewing thread, zipper tape, buttons, and other components selected as the same color number may look matched where they are checked, yet appear to be different colors at the sales destination or when worn. In particular, with colors that are close together, even slight differences can stand out.

Glossy materials, brushed materials, and sheer materials are also affected by reflected light and the influence of the base layer. For this reason, it is important to distinguish differences caused by metamerism from differences in appearance caused by surface shape and texture.

• The colors of the textile and accessories appear shifted under lighting
• Switching sections or stitching within the same product stand out
• There is no problem during daytime inspection, but differences appear under store lighting

Main Uses and Management Situations

In apparel, this should be considered for all items that use color coordination or same-color matching. It is especially effective to check from the planning stage for products such as jackets, suits, uniforms, and formalwear, where the body fabric and multiple accessories are matched in close colors.

Although the season itself is not a cause, caution is required for uses that are likely to be seen in both daylight outdoors and artificial lighting at night. Check not only the textile alone, but also the secondary materials that will actually be combined with it.

Selection and Handling Precautions

For color matching, assume the lighting conditions under which the final product will most often be seen, and check the textile and accessories side by side under multiple light sources. If possible, checking not only small swatches but also larger samples or sewing samples makes it easier to judge differences in switching sections and stitching.

Metamerism is not a phenomenon caused directly by shrinkage, washing, or sewing. However, if the color relationship changes due to fading, color transfer, or lot differences caused by washing or sunlight, differences in appearance may become more noticeable. Also check wash fastness and light fastness separately.

• Share the viewing light source as part of the approval conditions for color samples
• Check combinations of textile, lining, interlining, thread, zipper, and others
• For additional production, recheck with the possibility of a different lot in mind
• Do not confuse color matching with fastness evaluation

Differences from Similar Terms

Fastness is a quality property that indicates how difficult it is for color to change or transfer in response to washing, rubbing, sweat, light, and similar factors. In contrast, metamerism is a phenomenon in which the matching relationship between two colors appears to change mainly because of differences in the light source, and the object being evaluated is different.

Lot differences are variations in color, hand feel, and similar properties due to differences in production timing or production unit. Lot differences make color matching difficult, but even within the same lot, color differences can appear depending on the light source.

Frequently Asked Questions