Patent ID: 7810918

Claim:
A plurality of ink sticks for use in phase change ink imaging devices, the plurality of ink sticks comprising: a first ink stick having a first ink color and being configured with a first structural feature that identifies the first ink stick as having the first ink color and with a second structural feature that enables the first ink stick to be inserted through an insertion opening of an ink loader for a first model of a phase change ink imaging device and that enables the first ink stick to be inserted through an insertion opening of an ink loader for a second model of the phase change ink imaging device; and a second ink stick having the first ink color and being configured with the first structural feature that identifies the first and the second ink sticks as having the first ink color and with a third structural feature that enables the second ink stick to be inserted through the insertion opening of the ink loader for the second model of the phase change ink imaging device and that disables the second ink stick from being inserted through the insertion opening of the ink loader for the first model of the phase change ink imaging device; wherein the first and second ink sticks have substantially identical shapes except for the configurations of the second and the third structural features.