Why does changing the ink from Matte Black ink to Photo Black ink take more time and use more ink than changing it from Photo Black to Matte Black?

• The printer must flush all the Matte Black ink from the printer's ink damper and print head so the Photo Black ink will appear consistent and uniform when you print on glossy or semi-gloss media. The printer does not need to flush as much ink when you change ink from Photo Black ink to Matte Black ink.