Comparison of Visual Assessments for Colour Fastness Among Three Countries and the Relationship Between the Visual and the Instrumental Assessment

摘要

In a previous report, we examined the difference between the visual assessment of Japanese and Thai observers for colour fastness. A significant difference between two countries was found. Therefore, it is very important to examine whether the same tendency exists for other countries. In this report, data of Hong Kong were included in addition to those of Japan and Thailand. We carried out the same experi-ment as the previous one and compared the results of the visual assessments among the three countries. The properties of the visual assessment in each country for staining and change in colour were obtained. Because the difference among individuals and countries can not be avoided in the visual assessment, the instrumental method is more desirable, and the several objective methods have been proposed. We examined the relationship between the visual assessment of each country and the instrumental assess-ment. When comparing the visual assessments to the instrumental assessments for each of the three countries, the differences are greater than those between visual assessments of any two countries. There-fore, if we could develop a formula fit well using data from a country, it would be possible for this formula to be used in the other countries. From the results obtained in this study, we suggest the use of the instrumental assessment method instead of the visual assessment. Thus, the dependency of the colour fastness assessment on the indi-viduals and countries can be avoided.%グレースケールによる染色堅牢度評価における，国による違いを検討するために，前報では，日本とタイで同じ試料を用いて視感評価実験を行なった．視感評価は，汚染では，大きな違いは見られなかったが，変退色になるとかなりの差が見られた．本報では，日本，タイに加え香港でも同じ視感評価実験を行い，3国間で比較検討し，それぞれの国の特徴を見出した． 視感評価では，個人や国による違いは避けられないので，計測評価値が望まれ，いくつかの式が提案されている．そこで，それぞれの国で得られた視感評価値と提案されている計測評価値との関係を調べた．汚染および変退色試料において，計測評価値と視感評価値とを比較すると，国による視感評価値の差より，計測評価値間の差の方がかなり大きかった．したがって，ある国の視感評価値と良好に対応する計測評価値は，他の国においても概ね良好に対応すると考えられる． これらの結果からも，個人や国による差が避けられない視感評価値に代わり計測評価値が使われるようになることを期待する．