Epson Stylus Photo 750 User Manual page 16

Install the ink cartridge immediately after you remove it from its foil
package. Leaving the cartridge unpacked for a long time before use
may result in reduced print quality.
Do not use an ink cartridge beyond the date printed on the cartridge
package. For best results, use up the ink cartridges within six months
of installing them.
Do not shake an ink cartridge; this can cause leakage.
Always turn the printer off using the P power button. When you press
this button, the P power light flashes briefly then goes out. Do not
unplug the printer or turn off the power to the printer until the P power
light is off.
Before transporting the printer, make sure the print head is positioned
all the way to the right (capped) and the ink cartridges are in place.