Abstract
Kodak neutral test cards are evaluated as reflectance standards for use in field spectroscopy. Laboratory measurements of spectral reflectance over the range 400-1100 nm show that the consistency between cards selected from a single manufacturers batch is good. Cards chosen from different batches manufactured over the period 1983-1988 were more variable in reflectance, especially in the reflective infrared. Cards from different batches which had been used in the field under controlled conditions were less variable in reflectance than those which had not been used at all, but they had an average reflectance 1-2 per cent higher than new cards in Thematic Mapper bands 1-4.