Hello, Graeme. I've noticed that "-F" parameter didn't work together with "-q". For example: C:\Argyll_V1.3.5\bin>targen -v -d2 -p1.4 -w -f2880 -Q -F 0,0,0,25 Test iRGB test chart Full spread patches = 2880 Filtering out samples outside sphere at 0.000000 0.000000 0.000000 radius 25.000000 Added 2880/2880 Total number of patches = 64 Execution time = 1.593000 seconds C:\Argyll_V1.3.5\bin>targen -v -d2 -p1.4 -w -f2880 -q -F 0,0,0,25 Test iRGB test chart Full spread patches = 2880 Filtering out samples outside sphere at 0.000000 0.000000 0.000000 radius 25.000000 Added 2880/2880 Total number of patches = 2880 Execution time = 0.429000 seconds MS Windows Vista x86. Targen executable from ArgyllCMS site.