I'm looking for a set of test images. I recall reading about them on this site some time ago but simply cannot conjure up the right keywords to bring up the thread. Searching for "printer test image" or similar yields too much noise.
The set I'm thinking of had maybe 7 or 8 images, each focusing on a particular colour range: blues, greens, reds, yellows etc etc. They were quite pricey, as I recall.
Any ideas?