How do I switch between using the Photo Black and Matte Black inks?

You can swap the two inks directly by using the printer panel. The option to switch the black inks is available from the menus under the Maintenance section. The printer then does the rest; since the 3800 holds both PK and MK inks at the same time, you do not need to take one out to insert the other. You can also let the printer driver software handle the change automatically based on the selected Media Type. The Media Type list is divided into two categories, Photo Black (the top half) and Matte Black (the bottom half). See here for a list of available Media Types. If you select a Media Type from the PK section (e.g., Premium Luster), then the 3800 will print with PK. Similarly, if you select a Media Type from the MK section (e.g., Velvet Fine Art), then the 3800 will print with MK. Note that switching PK and MK inks does take some time (2 to 3 minutes) and wastes some ink (1.5 to 4 mL). See here for more details. For this reason, it is generally better to group your prints by black ...  more