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Search performance
Searchlists are intended to be used as an aid to visual color judgment. A number of
conditions affect the performance of the search process. In addition to the instrument
effects of sample type, sample presentation, and power quality which affect the
measurement process discussed earlier in this manual, there are several effects related
specifically to searchlists.
•
Searchlists are constructed for a single illuminant. The standard condition is for
daylight viewing (D65). The instrument finds the “closest” item in the searchlist
assuming that the items and the search target are viewed in daylight. To the extent
that the material and/or the search target would appear to shift their relative color
under other lighting conditions, visual judgment will differ from the instrument
results.
•
Searchlists are constructed from target color reflectance spectra. Ideally these are the
same targets used in the production of materials. In any measurement process and in
any manufacturing process there will be some expected variance. Ideally the target
spectra represent the center of the production variance. In fact most manufacturing
processes control their output to fall within a specified range, and the targets may be
at any point in this range. The physical materials of color systems in particular are
subject to pigment fading, vehicle discoloration, and substrate aging. The physical
condition, especially including age, of color materials will affect visual judgment.
•
Instruments are factory calibrated to a specific gray scale using specified materials
with a specified measurements geometry. At the time of shipment, instruments are
tested against specific performance requirements. Instrument specifications and
testing detail are available from your distributor. After shipment the instrument may
have its gray scale recalibrated, or have optical changes which affect its grayscale.
This type of change, along with gloss variation in materials, will lead to variation in
measured and apparent lightness. The default instrument setup chooses the “closest”
color giving equal weight to lightness and chroma variations. In some applications
visual judgement may tend to give lower weight to lightness variations and higher
weight to chroma variations.
Pantone, Inc. is not liable and takes no responsibilty for search list perfromance. Refer to
PANTONE Color Reference Publications for accurate color.
