The TC1617 is a collection of CMYK patches commonly used in profiling CMYK devices like printing presses. It contains a good sampling of the entire printable gamut, as well as the neutrals that are commonly used to calculate gray balance using the G7 method.
TC1617 is the common name for this target. The official name for this target is IT8.7/5.
This patch collection was created by removing the duplicate patches from the 1617-patch IT8.7/4 target, and replacing them with the K-only patches and the CMY-gray patches of the P2P51 target, resulting in a chart size that remained at 1617 patches.
While the IT8.7/4 chart was very popular in the industry as a profiling target, it lacked a good sampling of neutrals. The TC1617 resolves this issue and is highly recommended as a good CMYK profiling option in a compact size.