Ink Sac

Ink Sacs, formerly known as Ink Sacks, are obtained from squid by hitting or killing them and yield the darkest possible primary color dye.

Uses
The second recipe is not as cost-effective as making gray dye, then combining with another bone meal to make light gray dye. It yields 4 units of dye per ink sac vs. 3 in the first.
 * Make black wool by adding an Ink Sac to one block of wool.
 * Ink Sacs can be applied to sheep, but as of Beta 1.2, black sheep are naturally occurring.
 * Ink Sacs are a critical component of gray and light gray wool dyes.